diff --git a/include/os/freebsd/spl/sys/debug.h b/include/os/freebsd/spl/sys/debug.h
index 6df76db7ea..c3d7a6e83f 100644
--- a/include/os/freebsd/spl/sys/debug.h
+++ b/include/os/freebsd/spl/sys/debug.h
@@ -133,14 +133,20 @@ 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 ((uintptr_t)(x)))
+#define	ASSERT3B(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3S(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3U(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3P(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	IMPLY(A, B)							\
+	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
+#define	EQUIV(A, B)		\
+	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
 
 /*
  * Debugging enabled (--enable-debug)
diff --git a/include/os/linux/spl/sys/debug.h b/include/os/linux/spl/sys/debug.h
index 102fc640bf..e0ae7e2d6b 100644
--- a/include/os/linux/spl/sys/debug.h
+++ b/include/os/linux/spl/sys/debug.h
@@ -133,14 +133,20 @@ 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 ((uintptr_t)(x)))
+#define	ASSERT3B(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3S(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3U(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3P(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	IMPLY(A, B)							\
+	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
+#define	EQUIV(A, B)		\
+	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
 
 /*
  * Debugging enabled (--enable-debug)
diff --git a/lib/libspl/include/assert.h b/lib/libspl/include/assert.h
index fadff14cce..e129ef7df9 100644
--- a/lib/libspl/include/assert.h
+++ b/lib/libspl/include/assert.h
@@ -120,15 +120,21 @@ 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 ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3S(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3U(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT3P(x, y, z)						\
+	((void) sizeof ((uintptr_t)(x)), (void) sizeof ((uintptr_t)(z)))
+#define	ASSERT0(x)		((void) sizeof ((uintptr_t)(x)))
+#define	ASSERT(x)		((void) sizeof ((uintptr_t)(x)))
+#define	assert(x)		((void) sizeof ((uintptr_t)(x)))
+#define	IMPLY(A, B)							\
+	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
+#define	EQUIV(A, B)							\
+	((void) sizeof ((uintptr_t)(A)), (void) sizeof ((uintptr_t)(B)))
 #else
 #define	ASSERT3B	VERIFY3B
 #define	ASSERT3S	VERIFY3S