diff --git a/pkgs/development/python-modules/pillow-heif/default.nix b/pkgs/development/python-modules/pillow-heif/default.nix
index 6560c63ac283..d91408fc864d 100644
--- a/pkgs/development/python-modules/pillow-heif/default.nix
+++ b/pkgs/development/python-modules/pillow-heif/default.nix
@@ -57,8 +57,12 @@ buildPythonPackage rec {
     x265
   ];
 
-  # clang-16: error: argument unused during compilation: '-fno-strict-overflow' [-Werror,-Wunused-command-line-argument]
-  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-unused-command-line-argument";
+  env = {
+    # clang-16: error: argument unused during compilation: '-fno-strict-overflow'
+    NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-unused-command-line-argument";
+
+    RELEASE_FULL_FLAG = 1;
+  };
 
   propagatedBuildInputs = [
     pillow