diff --git a/pkgs/development/libraries/jemalloc/default.nix b/pkgs/development/libraries/jemalloc/default.nix
index cb734508b340..c505dc6db55a 100644
--- a/pkgs/development/libraries/jemalloc/default.nix
+++ b/pkgs/development/libraries/jemalloc/default.nix
@@ -1,6 +1,7 @@
 { lib
 , stdenv
 , fetchurl
+, fetchpatch
 # By default, jemalloc puts a je_ prefix onto all its symbols on OSX, which
 # then stops downstream builds (mariadb in particular) from detecting it. This
 # option should remove the prefix and give us a working jemalloc.
@@ -19,6 +20,14 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-LbgtHnEZ3z5xt2QCGbbf6EeJvAU3mDw7esT3GJrs/qo=";
   };
 
+  patches = [
+    # fix tests under --with-jemalloc-prefix=, see https://github.com/jemalloc/jemalloc/pull/2340
+    (fetchpatch {
+      url = "https://github.com/jemalloc/jemalloc/commit/d00ecee6a8dfa90afcb1bbc0858985c17bef6559.patch";
+      hash = "sha256-N5i4IxGJ4SSAgFiq5oGRnrNeegdk2flw9Sh2mP0yl4c=";
+    })
+  ];
+
   # see the comment on stripPrefix
   configureFlags = []
     ++ lib.optional stripPrefix "--with-jemalloc-prefix="
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index e0de8828f596..501816e95cf3 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -19733,11 +19733,7 @@ with pkgs;
 
   jbigkit = callPackage ../development/libraries/jbigkit { };
 
-  jemalloc = callPackage ../development/libraries/jemalloc {
-    # tests fail with LLVM 11+
-    # https://github.com/jemalloc/jemalloc/issues/2091
-    stdenv = if stdenv.cc.isClang then llvmPackages_10.stdenv else stdenv;
-  };
+  jemalloc = callPackage ../development/libraries/jemalloc { };
 
   jose = callPackage ../development/libraries/jose { };