diff --git a/core/clingutils/CMakeLists.txt b/core/clingutils/CMakeLists.txt
index b470eb1e654c9..0c8df994ecad5 100644
--- a/core/clingutils/CMakeLists.txt
+++ b/core/clingutils/CMakeLists.txt
@@ -107,7 +107,9 @@ set(clinginclude ${CMAKE_SOURCE_DIR}/interpreter/cling/include)
 
 set(custom_modulemaps)
 if (runtime_cxxmodules)
-  set(custom_modulemaps boost.modulemap tinyxml2.modulemap cuda.modulemap module.modulemap.build)
+  set(custom_modulemaps boost.modulemap tinyxml2.modulemap cuda.modulemap
+                        module.modulemap.build
+                        json.modulemap)
   # FIXME: We should install vc.modulemap only when Vc is found (Vc_FOUND) but
   # some systems install it under /usr/include/Vc/Vc which allows rootcling to
   # discover it and assert that the modulemap is not found.
diff --git a/graf3d/eve7/CMakeLists.txt b/graf3d/eve7/CMakeLists.txt
index 74aab3544551a..84fb2ab2a8b93 100644
--- a/graf3d/eve7/CMakeLists.txt
+++ b/graf3d/eve7/CMakeLists.txt
@@ -123,6 +123,8 @@ ROOT_STANDARD_LIBRARY_PACKAGE(ROOTEve
     src/REveViewer.cxx
     src/REveVSD.cxx
     src/REveVSDStructs.cxx
+  DICTIONARY_OPTIONS
+    -mByproduct Json
   DEPENDENCIES
     Core
     Geom
diff --git a/interpreter/cling/include/cling/json.modulemap b/interpreter/cling/include/cling/json.modulemap
new file mode 100644
index 0000000000000..758cf2d779e2c
--- /dev/null
+++ b/interpreter/cling/include/cling/json.modulemap
@@ -0,0 +1,4 @@
+module Json {
+  header "nlohmann/json.hpp"
+  export *
+}
diff --git a/interpreter/cling/lib/Interpreter/CIFactory.cpp b/interpreter/cling/lib/Interpreter/CIFactory.cpp
index 52e882507564c..0891130268de0 100644
--- a/interpreter/cling/lib/Interpreter/CIFactory.cpp
+++ b/interpreter/cling/lib/Interpreter/CIFactory.cpp
@@ -580,6 +580,7 @@ namespace {
     llvm::SmallString<256> tinyxml2IncLoc(getIncludePathForHeader(HS, "tinyxml2.h"));
     llvm::SmallString<256> cudaIncLoc(getIncludePathForHeader(HS, "cuda.h"));
     llvm::SmallString<256> vcVcIncLoc(getIncludePathForHeader(HS, "Vc/Vc"));
+    llvm::SmallString<256> jsonIncLoc(getIncludePathForHeader(HS, "nlohmann/json.hpp"));
     llvm::SmallString<256> clingIncLoc(getIncludePathForHeader(HS,
                                         "cling/Interpreter/RuntimeUniverse.h"));
 
@@ -705,6 +706,11 @@ namespace {
                               clingIncLoc.str(), MOverlay,
                               /*RegisterModuleMap=*/ true,
                               /*AllowModulemapOverride=*/ false);
+    if (!jsonIncLoc.empty())
+      maybeAppendOverlayEntry(jsonIncLoc.str(), "json.modulemap",
+                              clingIncLoc.str(), MOverlay,
+                              /*RegisterModuleMap=*/ true,
+                              /*AllowModulemapOverride=*/ false);
     if (!boostIncLoc.empty()) {
       // Add the modulemap in the include/boost folder not in include.
       llvm::sys::path::append(boostIncLoc, "boost");