diff --git a/src/App/Material.h b/src/App/Material.h
index b8a4156ebb..b0d1cf926e 100644
--- a/src/App/Material.h
+++ b/src/App/Material.h
@@ -284,10 +284,10 @@ public:
 
     bool operator==(const Material& m) const
     {
-        return _matType!=m._matType || shininess!=m.shininess ||
-            transparency!=m.transparency || ambientColor!=m.ambientColor ||
-            diffuseColor!=m.diffuseColor || specularColor!=m.specularColor ||
-            emissiveColor!=m.emissiveColor;
+        return _matType==m._matType && shininess==m.shininess &&
+            transparency==m.transparency && ambientColor==m.ambientColor &&
+            diffuseColor==m.diffuseColor && specularColor==m.specularColor &&
+            emissiveColor==m.emissiveColor;
     }
     bool operator!=(const Material& m) const
     {