Index: head/sys/geom/virstor/g_virstor.h
===================================================================
--- head/sys/geom/virstor/g_virstor.h
+++ head/sys/geom/virstor/g_virstor.h
@@ -48,8 +48,8 @@
 #define	LOG_MSG(lvl, ...)       do {					\
         if (g_virstor_debug >= (lvl)) {					\
                 printf("GEOM_" G_VIRSTOR_CLASS_NAME);			\
-                if (lvl > 0)						\
-                        printf("[%u]", lvl);				\
+                if ((lvl) > 0)						\
+                        printf("[%u]", (lvl));				\
                 printf(": ");						\
                 printf(__VA_ARGS__);					\
                 printf("\n");						\
@@ -60,8 +60,8 @@
 #define	LOG_REQ(lvl, bp, ...)  do {					\
         if (g_virstor_debug >= (lvl)) {					\
                 printf("GEOM_" G_VIRSTOR_CLASS_NAME);			\
-                if (lvl > 0)						\
-                        printf("[%u]", lvl);				\
+                if ((lvl) > 0)						\
+                        printf("[%u]", (lvl));				\
                 printf(": ");						\
                 printf(__VA_ARGS__);					\
                 printf(" ");						\