diff --git a/pkgs/development/compilers/llvm/common/flang/default.nix b/pkgs/development/compilers/llvm/common/flang/default.nix
index 5ddb77d74b2e..fbbae39d7365 100644
--- a/pkgs/development/compilers/llvm/common/flang/default.nix
+++ b/pkgs/development/compilers/llvm/common/flang/default.nix
@@ -60,6 +60,9 @@ stdenv.mkDerivation (finalAttrs: {
     libllvm.dev
     mlir.dev
   ];
+
+  strictDeps = true;
+
   preConfigure = ''
     ls -l ${libllvm.dev}/lib/cmake/llvm/LLVMConfig.cmake
     ls -l ${libclang.dev}/lib/cmake/clang/ClangConfig.cmake