diff --git a/pkgs/development/compilers/glslang/default.nix b/pkgs/development/compilers/glslang/default.nix
index 17ff68e892a2..1dd303170936 100644
--- a/pkgs/development/compilers/glslang/default.nix
+++ b/pkgs/development/compilers/glslang/default.nix
@@ -39,7 +39,7 @@ stdenv.mkDerivation rec {
   # Fix the paths in .pc, even though it's unclear if these .pc are really useful.
   postFixup = ''
     substituteInPlace "$out"/lib/pkgconfig/SPIRV-Tools{,-shared}.pc \
-      --replace '=''${prefix}//' '='
+      --replace '=''${prefix}//' '=/'
   '';
 
   meta = with lib; {