diff --git a/Source/cmNinjaTargetGenerator.cxx b/Source/cmNinjaTargetGenerator.cxx
index 816e6d827..b8cc5fbf8 100644
--- a/Source/cmNinjaTargetGenerator.cxx
+++ b/Source/cmNinjaTargetGenerator.cxx
@@ -454,7 +454,10 @@ cmNinjaTargetGenerator
   std::vector<std::string> compileCmds;
   cmSystemTools::ExpandListArgument(compileCmd, compileCmds);
 
-  compileCmds.front().insert(0, cldeps);
+  if (!compileCmds.empty())
+    {
+    compileCmds.front().insert(0, cldeps);
+    }
 
   for (std::vector<std::string>::iterator i = compileCmds.begin();
        i != compileCmds.end(); ++i)