diff --git a/tier1/KeyValues.cpp b/tier1/KeyValues.cpp
index 004eb024..e45695c0 100644
--- a/tier1/KeyValues.cpp
+++ b/tier1/KeyValues.cpp
@@ -13,6 +13,7 @@
 #define _alloca alloca
 #define _wtoi(arg) wcstol(arg, NULL, 10)
 #define _wtoi64(arg) wcstoll(arg, NULL, 10)
+#include <dlfcn.h>
 #endif
 
 #include <KeyValues.h>