diff --git a/src/os2/fontenum.cpp b/src/os2/fontenum.cpp
index b74beb0939..00454cee9b 100644
--- a/src/os2/fontenum.cpp
+++ b/src/os2/fontenum.cpp
@@ -17,6 +17,10 @@
 // headers
 // ----------------------------------------------------------------------------
 
+#ifdef __GNUG__
+    #pragma implementation "fontenum.h"
+#endif
+
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"