diff --git a/sys/alpha/include/mutex.h b/sys/alpha/include/mutex.h
index c8bcbdd90805..c141d6f017dd 100644
--- a/sys/alpha/include/mutex.h
+++ b/sys/alpha/include/mutex.h
@@ -39,7 +39,7 @@
 /* Global locks */
 extern struct mtx	clock_lock;
 
-#define	mtx_intr_enable(mutex)	(mutex)->mtx_savecrit = ALPHA_PSL_IPL_0
+#define	mtx_intr_enable(mutex)	do (mutex)->mtx_savecrit = ALPHA_PSL_IPL_0; while (0)
 
 #endif	/* _KERNEL */
 
diff --git a/sys/amd64/include/mutex.h b/sys/amd64/include/mutex.h
index b605efb3110d..b0fe512adcbb 100644
--- a/sys/amd64/include/mutex.h
+++ b/sys/amd64/include/mutex.h
@@ -40,7 +40,7 @@
 /* Global locks */
 extern struct mtx	clock_lock;
 
-#define	mtx_intr_enable(mutex)	(mutex)->mtx_savecrit |= PSL_I
+#define	mtx_intr_enable(mutex)	do (mutex)->mtx_savecrit |= PSL_I; while (0)
 
 /*
  * Assembly macros (for internal use only)
diff --git a/sys/i386/include/mutex.h b/sys/i386/include/mutex.h
index b605efb3110d..b0fe512adcbb 100644
--- a/sys/i386/include/mutex.h
+++ b/sys/i386/include/mutex.h
@@ -40,7 +40,7 @@
 /* Global locks */
 extern struct mtx	clock_lock;
 
-#define	mtx_intr_enable(mutex)	(mutex)->mtx_savecrit |= PSL_I
+#define	mtx_intr_enable(mutex)	do (mutex)->mtx_savecrit |= PSL_I; while (0)
 
 /*
  * Assembly macros (for internal use only)
diff --git a/sys/ia64/include/mutex.h b/sys/ia64/include/mutex.h
index f32bacd9aac5..2e7916c6bdfc 100644
--- a/sys/ia64/include/mutex.h
+++ b/sys/ia64/include/mutex.h
@@ -38,7 +38,7 @@
 
 #ifdef _KERNEL
 
-#define	mtx_intr_enable(mutex)	(mutex)->mtx_savecrit |= IA64_PSR_I
+#define	mtx_intr_enable(mutex)	do (mutex)->mtx_savecrit |= IA64_PSR_I; while (0)
 
 #endif	/* _KERNEL */
 
diff --git a/sys/powerpc/include/mutex.h b/sys/powerpc/include/mutex.h
index c8bcbdd90805..c141d6f017dd 100644
--- a/sys/powerpc/include/mutex.h
+++ b/sys/powerpc/include/mutex.h
@@ -39,7 +39,7 @@
 /* Global locks */
 extern struct mtx	clock_lock;
 
-#define	mtx_intr_enable(mutex)	(mutex)->mtx_savecrit = ALPHA_PSL_IPL_0
+#define	mtx_intr_enable(mutex)	do (mutex)->mtx_savecrit = ALPHA_PSL_IPL_0; while (0)
 
 #endif	/* _KERNEL */