diff --git a/Source/o_array.m b/Source/o_array.m
index 32257c26b..af8cabd0e 100644
--- a/Source/o_array.m
+++ b/Source/o_array.m
@@ -24,6 +24,7 @@
 
 /**** Included Headers *******************************************************/
 
+#include <gnustep/base/preface.h>
 #include <Foundation/NSZone.h>
 #include <gnustep/base/o_cbs.h>
 #include <gnustep/base/o_array.h>