diff --git a/src/libcore/rt/local_services.rs b/src/libcore/rt/local_services.rs
index a03bc6c409f8b..b83e1d2464890 100644
--- a/src/libcore/rt/local_services.rs
+++ b/src/libcore/rt/local_services.rs
@@ -220,4 +220,13 @@ mod test {
             assert!(result.is_err());
         }
     }
+
+    #[test]
+    fn rng() {
+        do run_in_newsched_task() {
+            use rand::{rng, Rng};
+            let r = rng();
+            let _ = r.next();
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/rt/rust_builtin.cpp b/src/rt/rust_builtin.cpp
index a491379153e1a..885b40c0a5062 100644
--- a/src/rt/rust_builtin.cpp
+++ b/src/rt/rust_builtin.cpp
@@ -88,8 +88,7 @@ rand_seed_size() {
 
 extern "C" CDECL void
 rand_gen_seed(uint8_t* dest, size_t size) {
-    rust_task *task = rust_get_current_task();
-    rng_gen_seed(task->kernel, dest, size);
+    rng_gen_seed(dest, size);
 }
 
 extern "C" CDECL void *
@@ -101,14 +100,14 @@ rand_new_seeded(uint8_t* seed, size_t seed_size) {
         task->fail();
         return NULL;
     }
-    rng_init(task->kernel, rng, seed, seed_size);
+    char *env_seed = task->kernel->env->rust_seed;
+    rng_init(rng, env_seed, seed, seed_size);
     return rng;
 }
 
 extern "C" CDECL uint32_t
 rand_next(rust_rng *rng) {
-    rust_task *task = rust_get_current_task();
-    return rng_gen_u32(task->kernel, rng);
+    return rng_gen_u32(rng);
 }
 
 extern "C" CDECL void
diff --git a/src/rt/rust_kernel.cpp b/src/rt/rust_kernel.cpp
index 761dbeade538b..bf48554696ebd 100644
--- a/src/rt/rust_kernel.cpp
+++ b/src/rt/rust_kernel.cpp
@@ -257,25 +257,6 @@ rust_kernel::generate_task_id() {
     return id;
 }
 
-#ifdef __WIN32__
-void
-rust_kernel::win32_require(LPCTSTR fn, BOOL ok) {
-    if (!ok) {
-        LPTSTR buf;
-        DWORD err = GetLastError();
-        FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
-                      FORMAT_MESSAGE_FROM_SYSTEM |
-                      FORMAT_MESSAGE_IGNORE_INSERTS,
-                      NULL, err,
-                      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                      (LPTSTR) &buf, 0, NULL );
-        KLOG_ERR_(dom, "%s failed with error %ld: %s", fn, err, buf);
-        LocalFree((HLOCAL)buf);
-        assert(ok);
-    }
-}
-#endif
-
 void
 rust_kernel::set_exit_status(int code) {
     scoped_lock with(rval_lock);
diff --git a/src/rt/rust_kernel.h b/src/rt/rust_kernel.h
index ec0515faeafc0..4976dec149a02 100644
--- a/src/rt/rust_kernel.h
+++ b/src/rt/rust_kernel.h
@@ -147,10 +147,6 @@ class rust_kernel {
     void wait_for_schedulers();
     int run();
 
-#ifdef __WIN32__
-    void win32_require(LPCTSTR fn, BOOL ok);
-#endif
-
     rust_task_id generate_task_id();
 
     void set_exit_status(int code);
diff --git a/src/rt/rust_rng.cpp b/src/rt/rust_rng.cpp
index 2c11691bf86b9..5cb91f4381187 100644
--- a/src/rt/rust_rng.cpp
+++ b/src/rt/rust_rng.cpp
@@ -12,6 +12,26 @@
 #include "rust_rng.h"
 #include "rust_util.h"
 
+
+#ifdef __WIN32__
+void
+win32_require(LPCTSTR fn, BOOL ok) {
+    if (!ok) {
+        LPTSTR buf;
+        DWORD err = GetLastError();
+        FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                      FORMAT_MESSAGE_FROM_SYSTEM |
+                      FORMAT_MESSAGE_IGNORE_INSERTS,
+                      NULL, err,
+                      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                      (LPTSTR) &buf, 0, NULL );
+        KLOG_ERR_(dom, "%s failed with error %ld: %s", fn, err, buf);
+        LocalFree((HLOCAL)buf);
+        assert(ok);
+    }
+}
+#endif
+
 size_t
 rng_seed_size() {
     randctx rctx;
@@ -21,44 +41,50 @@ rng_seed_size() {
 // Initialization helpers for ISAAC RNG
 
 void
-rng_gen_seed(rust_kernel* kernel, uint8_t* dest, size_t size) {
+rng_gen_seed(uint8_t* dest, size_t size) {
 #ifdef __WIN32__
     HCRYPTPROV hProv;
-    kernel->win32_require
+    win32_require
         (_T("CryptAcquireContext"),
          CryptAcquireContext(&hProv, NULL, NULL, PROV_RSA_FULL,
                              CRYPT_VERIFYCONTEXT|CRYPT_SILENT));
-    kernel->win32_require
+    win32_require
         (_T("CryptGenRandom"), CryptGenRandom(hProv, size, (BYTE*) dest));
-    kernel->win32_require
+    win32_require
         (_T("CryptReleaseContext"), CryptReleaseContext(hProv, 0));
 #else
     int fd = open("/dev/urandom", O_RDONLY);
-    if (fd == -1)
-        kernel->fatal("error opening /dev/urandom: %s", strerror(errno));
+    if (fd == -1) {
+        fprintf(stderr, "error opening /dev/urandom: %s", strerror(errno));
+        abort();
+    }
     size_t amount = 0;
     do {
         ssize_t ret = read(fd, dest+amount, size-amount);
-        if (ret < 0)
-            kernel->fatal("error reading /dev/urandom: %s", strerror(errno));
-        else if (ret == 0)
-            kernel->fatal("somehow hit eof reading from /dev/urandom");
+        if (ret < 0) {
+            fprintf(stderr, "error reading /dev/urandom: %s", strerror(errno));
+            abort();
+        }
+        else if (ret == 0) {
+            fprintf(stderr, "somehow hit eof reading from /dev/urandom");
+            abort();
+        }
         amount += (size_t)ret;
     } while (amount < size);
     int ret = close(fd);
-    // FIXME #3697: Why does this fail sometimes?
-    if (ret != 0)
-        kernel->log(log_warn, "error closing /dev/urandom: %s",
-            strerror(errno));
+    if (ret != 0) {
+        fprintf(stderr, "error closing /dev/urandom: %s", strerror(errno));
+        // FIXME #3697: Why does this fail sometimes?
+        // abort();
+    }
 #endif
 }
 
 static void
-isaac_init(rust_kernel *kernel, randctx *rctx,
+isaac_init(randctx *rctx, char *env_seed,
            uint8_t* user_seed, size_t seed_len) {
     memset(rctx, 0, sizeof(randctx));
 
-    char *env_seed = kernel->env->rust_seed;
     if (user_seed != NULL) {
         // ignore bytes after the required length
         if (seed_len > sizeof(rctx->randrsl)) {
@@ -72,8 +98,7 @@ isaac_init(rust_kernel *kernel, randctx *rctx,
             seed = (seed + 0x7ed55d16) + (seed << 12);
         }
     } else {
-        rng_gen_seed(kernel,
-                     (uint8_t*)&rctx->randrsl,
+        rng_gen_seed((uint8_t*)&rctx->randrsl,
                      sizeof(rctx->randrsl));
     }
 
@@ -81,14 +106,14 @@ isaac_init(rust_kernel *kernel, randctx *rctx,
 }
 
 void
-rng_init(rust_kernel* kernel, rust_rng* rng,
+rng_init(rust_rng* rng, char* env_seed,
          uint8_t *user_seed, size_t seed_len) {
-    isaac_init(kernel, &rng->rctx, user_seed, seed_len);
-    rng->reseedable = !user_seed && !kernel->env->rust_seed;
+    isaac_init(&rng->rctx, env_seed, user_seed, seed_len);
+    rng->reseedable = !user_seed && !env_seed;
 }
 
 static void
-rng_maybe_reseed(rust_kernel* kernel, rust_rng* rng) {
+rng_maybe_reseed(rust_rng* rng) {
     // If this RNG has generated more than 32KB of random data and was not
     // seeded by the user or RUST_SEED, then we should reseed now.
     const size_t RESEED_THRESHOLD = 32 * 1024;
@@ -96,16 +121,15 @@ rng_maybe_reseed(rust_kernel* kernel, rust_rng* rng) {
     if (bytes_generated < RESEED_THRESHOLD || !rng->reseedable) {
         return;
     }
-    rng_gen_seed(kernel,
-                 (uint8_t*)rng->rctx.randrsl,
+    rng_gen_seed((uint8_t*)rng->rctx.randrsl,
                  sizeof(rng->rctx.randrsl));
     randinit(&rng->rctx, 1);
 }
 
 uint32_t
-rng_gen_u32(rust_kernel* kernel, rust_rng* rng) {
+rng_gen_u32(rust_rng* rng) {
     uint32_t x = isaac_rand(&rng->rctx);
-    rng_maybe_reseed(kernel, rng);
+    rng_maybe_reseed(rng);
     return x;
 }
 
diff --git a/src/rt/rust_rng.h b/src/rt/rust_rng.h
index 3879b1138fa20..a13b5acd0eff2 100644
--- a/src/rt/rust_rng.h
+++ b/src/rt/rust_rng.h
@@ -23,11 +23,10 @@ struct rust_rng {
 };
 
 size_t rng_seed_size();
-void rng_gen_seed(rust_kernel* kernel,
-                  uint8_t* dest, size_t size);
-void rng_init(rust_kernel *kernel, rust_rng *rng,
+void rng_gen_seed(uint8_t* dest, size_t size);
+void rng_init(rust_rng *rng, char *env_seed,
               uint8_t *user_seed, size_t seed_len);
-uint32_t rng_gen_u32(rust_kernel *kernel, rust_rng *rng);
+uint32_t rng_gen_u32(rust_rng *rng);
 
 //
 // Local Variables:
diff --git a/src/rt/rust_sched_loop.cpp b/src/rt/rust_sched_loop.cpp
index 2911b970b1359..1f718df32aac9 100644
--- a/src/rt/rust_sched_loop.cpp
+++ b/src/rt/rust_sched_loop.cpp
@@ -43,7 +43,7 @@ rust_sched_loop::rust_sched_loop(rust_scheduler *sched, int id, bool killed) :
     name("main")
 {
     LOGPTR(this, "new dom", (uintptr_t)this);
-    rng_init(kernel, &rng, NULL, 0);
+    rng_init(&rng, kernel->env->rust_seed, NULL, 0);
 
     if (!tls_initialized)
         init_tls();
@@ -154,7 +154,7 @@ rust_sched_loop::schedule_task() {
     lock.must_have_lock();
     size_t tasks = running_tasks.length();
     if (tasks > 0) {
-        size_t i = (tasks > 1) ? (rng_gen_u32(kernel, &rng) % tasks) : 0;
+        size_t i = (tasks > 1) ? (rng_gen_u32(&rng) % tasks) : 0;
         return running_tasks[i];
     }
     return NULL;