diff --git a/src/smblib/smblib.h b/src/smblib/smblib.h
index afe926a4b5cd9ea8225b7dab58603466cbfa0313..4c9de40e2516189e4d2468333cb240f9725c5e23 100644
--- a/src/smblib/smblib.h
+++ b/src/smblib/smblib.h
@@ -82,7 +82,7 @@
 
 #define GETMSGTXT_TAILS 	1			/* Get message tail(s) too */
 
-#define SMB_IS_OPEN(smb)	(smb->shd_fp!=NULL)
+#define SMB_IS_OPEN(smb)	((smb)->shd_fp!=NULL)
 
 #ifdef __cplusplus
 extern "C" {