diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index ac5fec9c3..ab0d60ac3 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -3757,7 +3757,7 @@ void cmMakefile::GetListOfMacros(std::string& macros) const
     {
     macros += sep;
     macros += it->first;
-    sep = "";
+    sep = ";";
     }
 }