diff --git a/pkgs/os-specific/darwin/apple-source-releases/libsecurity_generic/default.nix b/pkgs/os-specific/darwin/apple-source-releases/libsecurity_generic/default.nix
index 6730e2424be..e8d0261beca 100644
--- a/pkgs/os-specific/darwin/apple-source-releases/libsecurity_generic/default.nix
+++ b/pkgs/os-specific/darwin/apple-source-releases/libsecurity_generic/default.nix
@@ -26,7 +26,7 @@ name: version: sha256: args: let
       '';
       preBuild = ''
         ln -s lib ${n}
-        makeFlagsArray=(-j''$NIX_BUILD_CORES)
+        makeFlagsArray=(-j$NIX_BUILD_CORES)
       '';
       buildInputs = [
         pkgs.gnustep.make
diff --git a/pkgs/os-specific/darwin/security-tool/default.nix b/pkgs/os-specific/darwin/security-tool/default.nix
index e6846aef750..ff35c292890 100644
--- a/pkgs/os-specific/darwin/security-tool/default.nix
+++ b/pkgs/os-specific/darwin/security-tool/default.nix
@@ -34,7 +34,7 @@ stdenv.mkDerivation rec {
   '';
 
   preBuild = ''
-    makeFlagsArray=(-j''$NIX_BUILD_CORES)
+    makeFlagsArray=(-j$NIX_BUILD_CORES)
   '';
 
   NIX_LDFLAGS = "-no_dtrace_dof";