diff --git a/src/makeg95.env b/src/makeg95.env
index 34d927865f..67df3d0a74 100644
--- a/src/makeg95.env
+++ b/src/makeg95.env
@@ -94,7 +94,12 @@ GUI = -D__WXMSW__ -D__WINDOWS__
 
 # Optimization
 # OPT = -O
-OPT =
+
+# according to Guillermo Rodriguez Garcia <guille@iies.es> this flag is needed
+# to make the standard div() functio work - otherwise it returns absolutely
+# incorrect results and completely breaks the wxImage class (where it's used
+# extensively)
+OPT = -fno-pcc-struct-return
 
 # Options for ar archiver
 # AROPTIONS = crs # For IRIX and Solaris (both SYSVR4).