diff --git a/pkgs/development/libraries/qt-5/5.5/qtwebsockets.nix b/pkgs/development/libraries/qt-5/5.5/qtwebsockets.nix
index fbdfbbcf0db..c0d0f9e7d71 100644
--- a/pkgs/development/libraries/qt-5/5.5/qtwebsockets.nix
+++ b/pkgs/development/libraries/qt-5/5.5/qtwebsockets.nix
@@ -3,4 +3,7 @@
 qtSubmodule {
   name = "qtwebsockets";
   qtInputs = [ qtbase qtdeclarative ];
+  postFixup = ''
+    fixQtModuleCMakeConfig "WebSockets"
+  '';
 }