diff --git a/sys/crypto/rijndael/rijndael-alg-fst.c b/sys/crypto/rijndael/rijndael-alg-fst.c
index 9f02aa648b05..5197e226a26e 100644
--- a/sys/crypto/rijndael/rijndael-alg-fst.c
+++ b/sys/crypto/rijndael/rijndael-alg-fst.c
@@ -33,6 +33,8 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #else
 #include <string.h>
+#include <assert.h>
+#define	KASSERT(exp, msg)	assert(exp)
 #endif
 
 #include <crypto/rijndael/rijndael.h>
@@ -734,10 +736,8 @@ int rijndaelKeySetupEnc(u32 rk[/*4*(Nr + 1)*/], const u8 cipherKey[], int keyBit
    	int i = 0;
 	u32 temp;
 
-#ifdef _KERNEL
 	KASSERT(keyBits == 128 || keyBits == 192 || keyBits == 256,
 	    ("Invalid key size (%d).", keyBits));
-#endif
 	rk[0] = GETU32(cipherKey     );
 	rk[1] = GETU32(cipherKey +  4);
 	rk[2] = GETU32(cipherKey +  8);