diff --git a/pkgs/development/libraries/qtscriptgenerator/default.nix b/pkgs/development/libraries/qtscriptgenerator/default.nix
index 75bd7b4dc7fb..8b257d299bf3 100644
--- a/pkgs/development/libraries/qtscriptgenerator/default.nix
+++ b/pkgs/development/libraries/qtscriptgenerator/default.nix
@@ -19,7 +19,8 @@ stdenv.mkDerivation {
     cd generator
     qmake
     make
-    ./generator
+    # Set QTDIR, see http://code.google.com/p/qtscriptgenerator/issues/detail?id=38
+    QTDIR=${qt4} ./generator
     cd ../qtbindings
     qmake
     make