diff --git a/Source/cmUseMangledMesaCommand.h b/Source/cmUseMangledMesaCommand.h
index 4fb68fa46..46aa10041 100644
--- a/Source/cmUseMangledMesaCommand.h
+++ b/Source/cmUseMangledMesaCommand.h
@@ -72,6 +72,12 @@ public:
       "being added to the include directory path earlier.";
     }
 
+  /** This command is kept for compatibility with older CMake versions. */
+  virtual bool IsDiscouraged()
+    {
+    return true;
+    }
+
 protected:
   void CopyAndFullPathMesaHeader(const char* source,
                                  const char* outdir);
diff --git a/Source/cmVariableRequiresCommand.h b/Source/cmVariableRequiresCommand.h
index becd108c5..28ef7bd93 100644
--- a/Source/cmVariableRequiresCommand.h
+++ b/Source/cmVariableRequiresCommand.h
@@ -72,6 +72,12 @@ public:
       "is reported.";
     }
   
+  /** This command is kept for compatibility with older CMake versions. */
+  virtual bool IsDiscouraged()
+    {
+    return true;
+    }
+
   cmTypeMacro(cmVariableRequiresCommand, cmCommand);
 };