diff --git a/sp/src/tier1/KeyValues.cpp b/sp/src/tier1/KeyValues.cpp
index 16fae59c..7ce91354 100644
--- a/sp/src/tier1/KeyValues.cpp
+++ b/sp/src/tier1/KeyValues.cpp
@@ -28,6 +28,9 @@
 #include "utlhash.h"
 #include "UtlSortVector.h"
 #include "convar.h"
+#ifdef MAPBASE
+#include "icommandline.h"
+#endif
 
 // memdbgon must be the last include file in a .cpp file!!!
 #include <tier0/memdbgon.h>