diff --git a/src/plugins/qt4projectmanager/qt4buildconfiguration.cpp b/src/plugins/qt4projectmanager/qt4buildconfiguration.cpp
index 96dc194..ad8d3a1 100644
--- a/src/plugins/qt4projectmanager/qt4buildconfiguration.cpp
+++ b/src/plugins/qt4projectmanager/qt4buildconfiguration.cpp
@@ -368,6 +368,9 @@ void Qt4BuildConfiguration::setToolChain(ProjectExplorer::ToolChain *tc)
     if (tc != 0 && !qt4Target()->possibleToolChains(this).contains(tc))
         return;
 
+    if (toolChain() != tc)
+        return;
+
     BuildConfiguration::setToolChain(tc);
 
     emit proFileEvaluateNeeded(this);