diff --git a/include/QF/GL/extensions.h b/include/QF/GL/extensions.h
index 118633e71..5d0b63d52 100644
--- a/include/QF/GL/extensions.h
+++ b/include/QF/GL/extensions.h
@@ -33,11 +33,18 @@
 #include "QF/GL/defines.h"
 #include "QF/GL/types.h"
 
-#ifdef _WIN32
-# include <windows.h>
-# define GLAPIENTRY WINAPI
-#else
-# define GLAPIENTRY
+// Define GLAPIENTRY to a useful value
+#ifndef GLAPIENTRY
+# ifdef _WIN32
+#  include <windows.h>
+#  define GLAPIENTRY WINAPI
+# else
+#  ifdef APIENTRY
+#   define GLAPIENTRY APIENTRY
+#  else
+#   define GLAPIENTRY
+#  endif
+# endif
 #endif
 
 // OpenGL numbers for extensions we use or want to use
diff --git a/include/QF/GL/funcs.h b/include/QF/GL/funcs.h
index 3a9844bc5..76a4f3113 100644
--- a/include/QF/GL/funcs.h
+++ b/include/QF/GL/funcs.h
@@ -33,6 +33,10 @@
 #include "QF/GL/types.h"
 #include "QF/qtypes.h"
 
+#ifdef _WIN32
+# include <windows.h>
+#endif
+
 #define QFGL_NEED(ret, name, args)	extern ret (GLAPIENTRY * qf##name) args
 #include "QF/GL/qf_funcs_list.h"
 #undef QFGL_NEED