diff --git a/pkgs/development/libraries/ilmbase/default.nix b/pkgs/development/libraries/ilmbase/default.nix
index 4ea16a59e8b..0244725177e 100644
--- a/pkgs/development/libraries/ilmbase/default.nix
+++ b/pkgs/development/libraries/ilmbase/default.nix
@@ -18,6 +18,9 @@ stdenv.mkDerivation rec {
     ./bootstrap
   '';
 
+  # otherwise, the pkgconfig info for the libraries will not match the filenames
+  configureFlags = stdenv.lib.optionalString stdenv.isDarwin "--enable-namespaceversioning=no";
+  
   depsBuildBuild = [ buildPackages.stdenv.cc ];
   nativeBuildInputs = [ automake autoconf libtool which ];
 
diff --git a/pkgs/development/libraries/openexr/default.nix b/pkgs/development/libraries/openexr/default.nix
index da8fb429465..81a5ab1db99 100644
--- a/pkgs/development/libraries/openexr/default.nix
+++ b/pkgs/development/libraries/openexr/default.nix
@@ -42,6 +42,9 @@ stdenv.mkDerivation rec {
     ./bootstrap
   '';
 
+  # otherwise, the pkgconfig info for the libraries will not match the filenames
+  configureFlags = stdenv.lib.optionalString stdenv.isDarwin "--enable-namespaceversioning=no";
+
   nativeBuildInputs = [ pkgconfig autoconf automake libtool ];
   propagatedBuildInputs = [ ilmbase zlib ];