diff --git a/ChangeLog b/ChangeLog
index 7d8e654..d149061 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2003-06-01  David Ayers  <d.ayers@inode.at>
+
+	* gdl2.make.in:  Set GDL2 as auxiliary preprocessor flag.
+
 2003-05-22  David Ayers  <d.ayers@inode.at>
 
 	* config/postgres.m4: Added /usr/include/postgresql to include
diff --git a/gdl2.make.in b/gdl2.make.in
index 16739b5..3501e0f 100644
--- a/gdl2.make.in
+++ b/gdl2.make.in
@@ -35,7 +35,11 @@ GDL2_MINOR_VERSION = @MINOR_VERSION@
 GDL2_SUBMINOR_VERSION = @SUBMINOR_VERSION@
 
 
-# Nothing special just include the library
+
+# Additional flags to pass to the preprocessor
+AUXILIARY_CPPFLAGS += -DGDL2
+
+# Additional libraries for the linker
 AUXILIARY_TOOL_LIBS += -lgnustep-db2 -lgnustep-db2control
 
 endif