diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 83164bea63dc..bfb3f6f0d019 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -2078,7 +2078,7 @@ static void prim_toFile(EvalState & state, const PosIdx pos, Value * * args, Val
         })
         : ({
             StringSource s { contents };
-            state.store->addToStoreFromDump(s, name, TextIngestionMethod {}, HashAlgorithm::SHA256, refs, state.repair);
+            state.store->addToStoreFromDump(s, name, FileSerialisationMethod::Flat, TextIngestionMethod {}, HashAlgorithm::SHA256, refs, state.repair);
         });
 
     /* Note: we don't need to add `context' to the context of the
diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index d6047dd7e67d..25bb291d1412 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -305,7 +305,8 @@ void BinaryCacheStore::addToStore(const ValidPathInfo & info, Source & narSource
 StorePath BinaryCacheStore::addToStoreFromDump(
     Source & dump,
     std::string_view name,
-    ContentAddressMethod method,
+    FileSerialisationMethod dumpMethod,
+    ContentAddressMethod hashMethod,
     HashAlgorithm hashAlgo,
     const StorePathSet & references,
     RepairFlag repair)
@@ -313,17 +314,26 @@ StorePath BinaryCacheStore::addToStoreFromDump(
     std::optional<Hash> caHash;
     std::string nar;
 
+    // Calculating Git hash from NAR stream not yet implemented. May not
+    // be possible to implement in single-pass in NAR is in an
+    // inconvenient order. Could fetch after uploading, however.
+    if (hashMethod.getFileIngestionMethod() == FileIngestionMethod::Git)
+        unsupported("addToStoreFromDump");
+
     if (auto * dump2p = dynamic_cast<StringSource *>(&dump)) {
         auto & dump2 = *dump2p;
         // Hack, this gives us a "replayable" source so we can compute
         // multiple hashes more easily.
-        caHash = hashString(HashAlgorithm::SHA256, dump2.s);
-        switch (method.getFileIngestionMethod()) {
-        case FileIngestionMethod::Recursive:
+        //
+        // Only calculate if the dump is in the right format, however.
+        if (static_cast<FileIngestionMethod>(dumpMethod) == hashMethod.getFileIngestionMethod())
+            caHash = hashString(HashAlgorithm::SHA256, dump2.s);
+        switch (dumpMethod) {
+        case FileSerialisationMethod::Recursive:
             // The dump is already NAR in this case, just use it.
             nar = dump2.s;
             break;
-        case FileIngestionMethod::Flat:
+        case FileSerialisationMethod::Flat:
         {
             // The dump is Flat, so we need to convert it to NAR with a
             // single file.
@@ -332,14 +342,11 @@ StorePath BinaryCacheStore::addToStoreFromDump(
             nar = std::move(s.s);
             break;
         }
-        case FileIngestionMethod::Git:
-            unsupported("addToStoreFromDump");
-            break;
         }
     } else {
         // Otherwise, we have to do th same hashing as NAR so our single
         // hash will suffice for both purposes.
-        if (method != FileIngestionMethod::Recursive || hashAlgo != HashAlgorithm::SHA256)
+        if (dumpMethod != FileSerialisationMethod::Recursive || hashAlgo != HashAlgorithm::SHA256)
             unsupported("addToStoreFromDump");
     }
     StringSource narDump { nar };
@@ -354,7 +361,7 @@ StorePath BinaryCacheStore::addToStoreFromDump(
             *this,
             name,
             ContentAddressWithReferences::fromParts(
-                method,
+                hashMethod,
                 caHash ? *caHash : nar.first,
                 {
                     .others = references,
diff --git a/src/libstore/binary-cache-store.hh b/src/libstore/binary-cache-store.hh
index 76de2d11addf..7c282830933f 100644
--- a/src/libstore/binary-cache-store.hh
+++ b/src/libstore/binary-cache-store.hh
@@ -125,7 +125,8 @@ public:
     StorePath addToStoreFromDump(
         Source & dump,
         std::string_view name,
-        ContentAddressMethod method,
+        FileSerialisationMethod dumpMethod,
+        ContentAddressMethod hashMethod,
         HashAlgorithm hashAlgo,
         const StorePathSet & references,
         RepairFlag repair) override;
diff --git a/src/libstore/build/local-derivation-goal.cc b/src/libstore/build/local-derivation-goal.cc
index d92966a7432d..a9b8de123603 100644
--- a/src/libstore/build/local-derivation-goal.cc
+++ b/src/libstore/build/local-derivation-goal.cc
@@ -1312,12 +1312,13 @@ struct RestrictedStore : public virtual RestrictedStoreConfig, public virtual In
     StorePath addToStoreFromDump(
         Source & dump,
         std::string_view name,
-        ContentAddressMethod method,
+        FileSerialisationMethod dumpMethod,
+        ContentAddressMethod hashMethod,
         HashAlgorithm hashAlgo,
         const StorePathSet & references,
         RepairFlag repair) override
     {
-        auto path = next->addToStoreFromDump(dump, name, method, hashAlgo, references, repair);
+        auto path = next->addToStoreFromDump(dump, name, dumpMethod, hashMethod, hashAlgo, references, repair);
         goal.addDependency(path);
         return path;
     }
diff --git a/src/libstore/daemon.cc b/src/libstore/daemon.cc
index 873065e14744..e1337f51df3c 100644
--- a/src/libstore/daemon.cc
+++ b/src/libstore/daemon.cc
@@ -401,11 +401,23 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
             logger->startWork();
             auto pathInfo = [&]() {
                 // NB: FramedSource must be out of scope before logger->stopWork();
-                auto [contentAddressMethod, hashAlgo_] = ContentAddressMethod::parseWithAlgo(camStr);
-                auto hashAlgo = hashAlgo_; // work around clang bug
+                auto [contentAddressMethod, hashAlgo] = ContentAddressMethod::parseWithAlgo(camStr);
                 FramedSource source(from);
+                FileSerialisationMethod dumpMethod;
+                switch (contentAddressMethod.getFileIngestionMethod()) {
+                case FileIngestionMethod::Flat:
+                    dumpMethod = FileSerialisationMethod::Flat;
+                    break;
+                case FileIngestionMethod::Recursive:
+                    dumpMethod = FileSerialisationMethod::Recursive;
+                    break;
+                case FileIngestionMethod::Git:
+                    // Use NAR; Git is not a serialization method
+                    dumpMethod = FileSerialisationMethod::Recursive;
+                    break;
+                }
                 // TODO these two steps are essentially RemoteStore::addCAToStore. Move it up to Store.
-                auto path = store->addToStoreFromDump(source, name, contentAddressMethod, hashAlgo, refs, repair);
+                auto path = store->addToStoreFromDump(source, name, dumpMethod, contentAddressMethod, hashAlgo, refs, repair);
                 return store->queryPathInfo(path);
             }();
             logger->stopWork();
@@ -431,34 +443,23 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
                 hashAlgo = parseHashAlgo(hashAlgoRaw);
             }
 
+            // Old protocol always sends NAR, regardless of hashing method
             auto dumpSource = sinkToSource([&](Sink & saved) {
-                if (method == FileIngestionMethod::Recursive) {
-                    /* We parse the NAR dump through into `saved` unmodified,
-                       so why all this extra work? We still parse the NAR so
-                       that we aren't sending arbitrary data to `saved`
-                       unwittingly`, and we know when the NAR ends so we don't
-                       consume the rest of `from` and can't parse another
-                       command. (We don't trust `addToStoreFromDump` to not
-                       eagerly consume the entire stream it's given, past the
-                       length of the Nar. */
-                    TeeSource savedNARSource(from, saved);
-                    NullFileSystemObjectSink sink; /* just parse the NAR */
-                    parseDump(sink, savedNARSource);
-                } else if (method == FileIngestionMethod::Flat) {
-                    /* Incrementally parse the NAR file, stripping the
-                       metadata, and streaming the sole file we expect into
-                       `saved`. */
-                    RegularFileSink savedRegular { saved };
-                    parseDump(savedRegular, from);
-                    if (!savedRegular.regular) throw Error("regular file expected");
-                } else {
-                    /* Should have validated above that no other file ingestion
-                       method was used. */
-                    assert(false);
-                }
+                /* We parse the NAR dump through into `saved` unmodified,
+                   so why all this extra work? We still parse the NAR so
+                   that we aren't sending arbitrary data to `saved`
+                   unwittingly`, and we know when the NAR ends so we don't
+                   consume the rest of `from` and can't parse another
+                   command. (We don't trust `addToStoreFromDump` to not
+                   eagerly consume the entire stream it's given, past the
+                   length of the Nar. */
+                TeeSource savedNARSource(from, saved);
+                NullFileSystemObjectSink sink; /* just parse the NAR */
+                parseDump(sink, savedNARSource);
             });
             logger->startWork();
-            auto path = store->addToStoreFromDump(*dumpSource, baseName, method, hashAlgo);
+            auto path = store->addToStoreFromDump(
+                *dumpSource, baseName, FileSerialisationMethod::Recursive, method, hashAlgo);
             logger->stopWork();
 
             to << store->printStorePath(path);
@@ -490,7 +491,7 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         auto path = ({
             StringSource source { s };
-            store->addToStoreFromDump(source, suffix, TextIngestionMethod {}, HashAlgorithm::SHA256, refs, NoRepair);
+            store->addToStoreFromDump(source, suffix, FileSerialisationMethod::Flat, TextIngestionMethod {}, HashAlgorithm::SHA256, refs, NoRepair);
         });
         logger->stopWork();
         to << store->printStorePath(path);
diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 36042c06c393..ca849472e5ba 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -150,7 +150,7 @@ StorePath writeDerivation(Store & store,
         })
         : ({
             StringSource s { contents };
-            store.addToStoreFromDump(s, suffix, TextIngestionMethod {}, HashAlgorithm::SHA256, references, repair);
+            store.addToStoreFromDump(s, suffix, FileSerialisationMethod::Flat, TextIngestionMethod {}, HashAlgorithm::SHA256, references, repair);
         });
 }
 
diff --git a/src/libstore/dummy-store.cc b/src/libstore/dummy-store.cc
index e4f13b8f4100..30f23cff91a4 100644
--- a/src/libstore/dummy-store.cc
+++ b/src/libstore/dummy-store.cc
@@ -61,7 +61,8 @@ struct DummyStore : public virtual DummyStoreConfig, public virtual Store
     virtual StorePath addToStoreFromDump(
         Source & dump,
         std::string_view name,
-        ContentAddressMethod method = FileIngestionMethod::Recursive,
+        FileSerialisationMethod dumpMethod = FileSerialisationMethod::Recursive,
+        ContentAddressMethod hashMethod = FileIngestionMethod::Recursive,
         HashAlgorithm hashAlgo = HashAlgorithm::SHA256,
         const StorePathSet & references = StorePathSet(),
         RepairFlag repair = NoRepair) override
diff --git a/src/libstore/legacy-ssh-store.hh b/src/libstore/legacy-ssh-store.hh
index ae890177b3d5..ca2f115d25e4 100644
--- a/src/libstore/legacy-ssh-store.hh
+++ b/src/libstore/legacy-ssh-store.hh
@@ -72,7 +72,8 @@ struct LegacySSHStore : public virtual LegacySSHStoreConfig, public virtual Stor
     virtual StorePath addToStoreFromDump(
         Source & dump,
         std::string_view name,
-        ContentAddressMethod method = FileIngestionMethod::Recursive,
+        FileSerialisationMethod dumpMethod = FileSerialisationMethod::Recursive,
+        ContentAddressMethod hashMethod = FileIngestionMethod::Recursive,
         HashAlgorithm hashAlgo = HashAlgorithm::SHA256,
         const StorePathSet & references = StorePathSet(),
         RepairFlag repair = NoRepair) override
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 5f35cf3a856b..56f8c5dd85c9 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -1148,7 +1148,8 @@ void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
 StorePath LocalStore::addToStoreFromDump(
     Source & source0,
     std::string_view name,
-    ContentAddressMethod method,
+    FileSerialisationMethod dumpMethod,
+    ContentAddressMethod hashMethod,
     HashAlgorithm hashAlgo,
     const StorePathSet & references,
     RepairFlag repair)
@@ -1201,7 +1202,13 @@ StorePath LocalStore::addToStoreFromDump(
     Path tempDir;
     AutoCloseFD tempDirFd;
 
-    if (!inMemory) {
+    bool methodsMatch = (FileIngestionMethod) dumpMethod == hashMethod;
+
+    /* If the methods don't match, our streaming hash of the dump is the
+       wrong sort, and we need to rehash. */
+    bool inMemoryAndDontNeedRestore = inMemory && methodsMatch;
+
+    if (!inMemoryAndDontNeedRestore) {
         /* Drain what we pulled so far, and then keep on pulling */
         StringSource dumpSource { dump };
         ChainSource bothSource { dumpSource, source };
@@ -1210,40 +1217,23 @@ StorePath LocalStore::addToStoreFromDump(
         delTempDir = std::make_unique<AutoDelete>(tempDir);
         tempPath = tempDir + "/x";
 
-        auto fim = method.getFileIngestionMethod();
-        switch (fim) {
-        case FileIngestionMethod::Flat:
-        case FileIngestionMethod::Recursive:
-            restorePath(tempPath, bothSource, (FileSerialisationMethod) fim);
-            break;
-        case FileIngestionMethod::Git: {
-            RestoreSink sink;
-            sink.dstPath = tempPath;
-            auto accessor = getFSAccessor();
-            git::restore(sink, bothSource, [&](Hash childHash) {
-                return std::pair<SourceAccessor *, CanonPath> {
-                    &*accessor,
-                    CanonPath {
-                        printStorePath(this->makeFixedOutputPath("git", FixedOutputInfo {
-                            .method = FileIngestionMethod::Git,
-                            .hash = childHash,
-                        }))
-                    },
-                };
-            });
-            break;
-        }
-        }
+        restorePath(tempPath, bothSource, dumpMethod);
 
         dumpBuffer.reset();
         dump = {};
     }
 
-    auto [hash, size] = hashSink->finish();
+    auto [dumpHash, size] = hashSink->finish();
+
+    PosixSourceAccessor accessor;
 
     auto desc = ContentAddressWithReferences::fromParts(
-        method,
-        hash,
+        hashMethod,
+        methodsMatch
+            ? dumpHash
+            : hashPath(
+                accessor, CanonPath { tempPath },
+                hashMethod.getFileIngestionMethod(), hashAlgo),
         {
             .others = references,
             // caller is not capable of creating a self-reference, because this is content-addressed without modulus
@@ -1269,32 +1259,19 @@ StorePath LocalStore::addToStoreFromDump(
 
             autoGC();
 
-            if (inMemory) {
+            if (inMemoryAndDontNeedRestore) {
                 StringSource dumpSource { dump };
                 /* Restore from the buffer in memory. */
-                auto fim = method.getFileIngestionMethod();
+                auto fim = hashMethod.getFileIngestionMethod();
                 switch (fim) {
                 case FileIngestionMethod::Flat:
                 case FileIngestionMethod::Recursive:
                     restorePath(realPath, dumpSource, (FileSerialisationMethod) fim);
                     break;
-                case FileIngestionMethod::Git: {
-                    RestoreSink sink;
-                    sink.dstPath = realPath;
-                    auto accessor = getFSAccessor();
-                    git::restore(sink, dumpSource, [&](Hash childHash) {
-                        return std::pair<SourceAccessor *, CanonPath> {
-                            &*accessor,
-                            CanonPath {
-                                printStorePath(this->makeFixedOutputPath("git", FixedOutputInfo {
-                                    .method = FileIngestionMethod::Git,
-                                    .hash = childHash,
-                                }))
-                            },
-                        };
-                    });
-                    break;
-                }
+                case FileIngestionMethod::Git:
+                    // doesn't correspond to serialization method, so
+                    // this should be unreachable
+                    assert(false);
                 }
             } else {
                 /* Move the temporary path we restored above. */
@@ -1303,8 +1280,8 @@ StorePath LocalStore::addToStoreFromDump(
 
             /* For computing the nar hash. In recursive SHA-256 mode, this
                is the same as the store hash, so no need to do it again. */
-            auto narHash = std::pair { hash, size };
-            if (method != FileIngestionMethod::Recursive || hashAlgo != HashAlgorithm::SHA256) {
+            auto narHash = std::pair { dumpHash, size };
+            if (dumpMethod != FileSerialisationMethod::Recursive || hashAlgo != HashAlgorithm::SHA256) {
                 HashSink narSink { HashAlgorithm::SHA256 };
                 dumpPath(realPath, narSink);
                 narHash = narSink.finish();
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index ba56d3ead125..7eff1d6905ea 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -180,7 +180,8 @@ public:
     StorePath addToStoreFromDump(
         Source & dump,
         std::string_view name,
-        ContentAddressMethod method,
+        FileSerialisationMethod dumpMethod,
+        ContentAddressMethod hashMethod,
         HashAlgorithm hashAlgo,
         const StorePathSet & references,
         RepairFlag repair) override;
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index 0cae84828d37..8dfe8addab79 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -509,12 +509,28 @@ ref<const ValidPathInfo> RemoteStore::addCAToStore(
 StorePath RemoteStore::addToStoreFromDump(
     Source & dump,
     std::string_view name,
-    ContentAddressMethod method,
+    FileSerialisationMethod dumpMethod,
+    ContentAddressMethod hashMethod,
     HashAlgorithm hashAlgo,
     const StorePathSet & references,
     RepairFlag repair)
 {
-    return addCAToStore(dump, name, method, hashAlgo, references, repair)->path;
+    FileSerialisationMethod fsm;
+    switch (hashMethod.getFileIngestionMethod()) {
+    case FileIngestionMethod::Flat:
+        fsm = FileSerialisationMethod::Flat;
+        break;
+    case FileIngestionMethod::Recursive:
+        fsm = FileSerialisationMethod::Recursive;
+        break;
+    case FileIngestionMethod::Git:
+        // Use NAR; Git is not a serialization method
+        fsm = FileSerialisationMethod::Recursive;
+        break;
+    }
+    if (fsm != dumpMethod)
+        unsupported("RemoteStore::addToStoreFromDump doesn't support this `dumpMethod` `hashMethod` combination");
+    return addCAToStore(dump, name, hashMethod, hashAlgo, references, repair)->path;
 }
 
 
diff --git a/src/libstore/remote-store.hh b/src/libstore/remote-store.hh
index c51a21375628..d630adc08b79 100644
--- a/src/libstore/remote-store.hh
+++ b/src/libstore/remote-store.hh
@@ -87,7 +87,8 @@ public:
     StorePath addToStoreFromDump(
         Source & dump,
         std::string_view name,
-        ContentAddressMethod method = FileIngestionMethod::Recursive,
+        FileSerialisationMethod dumpMethod = FileSerialisationMethod::Recursive,
+        ContentAddressMethod hashMethod = FileIngestionMethod::Recursive,
         HashAlgorithm hashAlgo = HashAlgorithm::SHA256,
         const StorePathSet & references = StorePathSet(),
         RepairFlag repair = NoRepair) override;
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index c44612ec51ac..4356296d45a8 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -197,40 +197,23 @@ StorePath Store::addToStore(
     PathFilter & filter,
     RepairFlag repair)
 {
+    FileSerialisationMethod fsm;
+    switch (method.getFileIngestionMethod()) {
+    case FileIngestionMethod::Flat:
+        fsm = FileSerialisationMethod::Flat;
+        break;
+    case FileIngestionMethod::Recursive:
+        fsm = FileSerialisationMethod::Recursive;
+        break;
+    case FileIngestionMethod::Git:
+        // Use NAR; Git is not a serialization method
+        fsm = FileSerialisationMethod::Recursive;
+        break;
+    }
     auto source = sinkToSource([&](Sink & sink) {
-        auto fim = method.getFileIngestionMethod();
-        switch (fim) {
-        case FileIngestionMethod::Flat:
-        case FileIngestionMethod::Recursive:
-        {
-            dumpPath(accessor, path, sink, (FileSerialisationMethod) fim, filter);
-            break;
-        }
-        case FileIngestionMethod::Git:
-        {
-            git::dump(
-                accessor, path,
-                sink,
-                // recursively add to store if path is a directory
-                [&](const CanonPath & path) -> git::TreeEntry {
-                    auto storePath = addToStore("git", accessor, path, method, hashAlgo, references, filter, repair);
-                    auto info = queryPathInfo(storePath);
-                    assert(info->ca);
-                    assert(info->ca->method == FileIngestionMethod::Git);
-                    auto stat = getFSAccessor()->lstat(CanonPath(printStorePath(storePath)));
-                    auto gitModeOpt = git::convertMode(stat.type);
-                    assert(gitModeOpt);
-                    return {
-                        .mode = *gitModeOpt,
-                        .hash = info->ca->hash,
-                    };
-                },
-                filter);
-            break;
-        }
-        }
+        dumpPath(accessor, path, sink, fsm, filter);
     });
-    return addToStoreFromDump(*source, name, method, hashAlgo, references, repair);
+    return addToStoreFromDump(*source, name, fsm, method, hashAlgo, references, repair);
 }
 
 void Store::addMultipleToStore(
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 5163070b2e6d..5f683a21139f 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -466,14 +466,23 @@ public:
      * in `dump`, which is either a NAR serialisation (if recursive ==
      * true) or simply the contents of a regular file (if recursive ==
      * false).
-     * `dump` may be drained
      *
-     * \todo remove?
+     * `dump` may be drained.
+     *
+     * @param dumpMethod What serialisation format is `dump`, i.e. how
+     * to deserialize it. Must either match hashMethod or be
+     * `FileSerialisationMethod::Recursive`.
+     *
+     * @param hashMethod How content addressing? Need not match be the
+     * same as `dumpMethod`.
+     *
+     * @todo remove?
      */
     virtual StorePath addToStoreFromDump(
         Source & dump,
         std::string_view name,
-        ContentAddressMethod method = FileIngestionMethod::Recursive,
+        FileSerialisationMethod dumpMethod = FileSerialisationMethod::Recursive,
+        ContentAddressMethod hashMethod = FileIngestionMethod::Recursive,
         HashAlgorithm hashAlgo = HashAlgorithm::SHA256,
         const StorePathSet & references = StorePathSet(),
         RepairFlag repair = NoRepair) = 0;
@@ -772,7 +781,7 @@ protected:
      * Helper for methods that are not unsupported: this is used for
      * default definitions for virtual methods that are meant to be overriden.
      *
-     * \todo Using this should be a last resort. It is better to make
+     * @todo Using this should be a last resort. It is better to make
      * the method "virtual pure" and/or move it to a subclass.
      */
     [[noreturn]] void unsupported(const std::string & op)
diff --git a/src/nix-env/user-env.cc b/src/nix-env/user-env.cc
index 2f9c988d5f20..8bebe2b9eeee 100644
--- a/src/nix-env/user-env.cc
+++ b/src/nix-env/user-env.cc
@@ -113,7 +113,7 @@ bool createUserEnv(EvalState & state, PackageInfos & elems,
         std::string str2 = str.str();
         StringSource source { str2 };
         state.store->addToStoreFromDump(
-            source, "env-manifest.nix", TextIngestionMethod {}, HashAlgorithm::SHA256, references);
+            source, "env-manifest.nix", FileSerialisationMethod::Flat, TextIngestionMethod {}, HashAlgorithm::SHA256, references);
     });
 
     /* Get the environment builder expression. */
diff --git a/src/nix/develop.cc b/src/nix/develop.cc
index 403178a5d96e..c1842f2d57aa 100644
--- a/src/nix/develop.cc
+++ b/src/nix/develop.cc
@@ -226,7 +226,7 @@ static StorePath getDerivationEnvironment(ref<Store> store, ref<Store> evalStore
     auto getEnvShPath = ({
         StringSource source { getEnvSh };
         evalStore->addToStoreFromDump(
-            source, "get-env.sh", TextIngestionMethod {}, HashAlgorithm::SHA256, {});
+            source, "get-env.sh", FileSerialisationMethod::Flat, TextIngestionMethod {}, HashAlgorithm::SHA256, {});
     });
 
     drv.args = {store->printStorePath(getEnvShPath)};