diff --git a/include/os/freebsd/spl/sys/debug.h b/include/os/freebsd/spl/sys/debug.h
index 6a0c2fe07965..1c57b18441da 100644
--- a/include/os/freebsd/spl/sys/debug.h
+++ b/include/os/freebsd/spl/sys/debug.h
@@ -133,14 +133,14 @@ void spl_dumpstack(void);
  */
 #ifdef NDEBUG
 
-#define	ASSERT(x)		((void)sizeof(x))
-#define	ASSERT3B(x,y,z)		((void)sizeof(x), (void)sizeof(z))
-#define	ASSERT3S(x,y,z)		((void)sizeof(x), (void)sizeof(z))
-#define	ASSERT3U(x,y,z)		((void)sizeof(x), (void)sizeof(z))
-#define	ASSERT3P(x,y,z)		((void)sizeof(x), (void)sizeof(z))
-#define	ASSERT0(x)		((void)sizeof(x))
-#define	IMPLY(A, B)		((void)sizeof(A), (void)sizeof(B))
-#define	EQUIV(A, B)		((void)sizeof(A), (void)sizeof(B))
+#define	ASSERT(x)		((void) sizeof (x + 0))
+#define	ASSERT3B(x,y,z)		((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3S(x,y,z)		((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3U(x,y,z)		((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3P(x,y,z)		((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT0(x)		((void) sizeof (x + 0))
+#define	IMPLY(A, B)		((void) sizeof (A + 0), (void) sizeof (B + 0))
+#define	EQUIV(A, B)		((void) sizeof (A + 0), (void) sizeof (B + 0))
 
 /*
  * Debugging enabled (--enable-debug)
diff --git a/include/os/linux/spl/sys/debug.h b/include/os/linux/spl/sys/debug.h
index e3cbf62d1302..a517fef92ac5 100644
--- a/include/os/linux/spl/sys/debug.h
+++ b/include/os/linux/spl/sys/debug.h
@@ -133,14 +133,14 @@ void spl_dumpstack(void);
  */
 #ifdef NDEBUG
 
-#define	ASSERT(x)		((void)sizeof(x))
-#define	ASSERT3B(x,y,z)		((void)sizeof(x), (void)sizeof(z))
-#define	ASSERT3S(x,y,z)		((void)sizeof(x), (void)sizeof(z))
-#define	ASSERT3U(x,y,z)		((void)sizeof(x), (void)sizeof(z))
-#define	ASSERT3P(x,y,z)		((void)sizeof(x), (void)sizeof(z))
-#define	ASSERT0(x)		((void)sizeof(x))
-#define	IMPLY(A, B)		((void)sizeof(A), (void)sizeof(B))
-#define	EQUIV(A, B)		((void)sizeof(A), (void)sizeof(B))
+#define	ASSERT(x)		((void) sizeof (x + 0))
+#define	ASSERT3B(x,y,z)		((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3S(x,y,z)		((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3U(x,y,z)		((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3P(x,y,z)		((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT0(x)		((void) sizeof (x + 0))
+#define	IMPLY(A, B)		((void) sizeof (A + 0), (void) sizeof (B + 0))
+#define	EQUIV(A, B)		((void) sizeof (A + 0), (void) sizeof (B + 0))
 
 /*
  * Debugging enabled (--enable-debug)
diff --git a/lib/libspl/include/assert.h b/lib/libspl/include/assert.h
index 2a6e8a1e4e4f..5996ece0bb27 100644
--- a/lib/libspl/include/assert.h
+++ b/lib/libspl/include/assert.h
@@ -120,15 +120,15 @@ do {									\
 	__compile_time_assertion__ ## y[(x) ? 1 : -1]
 
 #ifdef NDEBUG
-#define	ASSERT3B(x, y, z)	((void) sizeof (x), (void) sizeof (z))
-#define	ASSERT3S(x, y, z)	((void) sizeof (x), (void) sizeof (z))
-#define	ASSERT3U(x, y, z)	((void) sizeof (x), (void) sizeof (z))
-#define	ASSERT3P(x, y, z)	((void) sizeof (x), (void) sizeof (z))
-#define	ASSERT0(x)		((void) sizeof (x))
-#define	ASSERT(x)		((void) sizeof (x))
-#define	assert(x)		((void) sizeof (x))
-#define	IMPLY(A, B)		((void) sizeof (A), (void) sizeof (B))
-#define	EQUIV(A, B)		((void) sizeof (A), (void) sizeof (B))
+#define	ASSERT3B(x, y, z)	((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3S(x, y, z)	((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3U(x, y, z)	((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT3P(x, y, z)	((void) sizeof (x + 0), (void) sizeof (z + 0))
+#define	ASSERT0(x)		((void) sizeof (x + 0))
+#define	ASSERT(x)		((void) sizeof (x + 0))
+#define	assert(x)		((void) sizeof (x + 0))
+#define	IMPLY(A, B)		((void) sizeof (A + 0), (void) sizeof (B + 0))
+#define	EQUIV(A, B)		((void) sizeof (A + 0), (void) sizeof (B + 0))
 #else
 #define	ASSERT3B	VERIFY3B
 #define	ASSERT3S	VERIFY3S