diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index 3699995..a832426 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -233,6 +233,8 @@
 		return blkcipher_walk_done(desc, walk, -EINVAL);
 	}
 
+	bsize = min(walk->walk_blocksize, n);
+
 	walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
 			 BLKCIPHER_WALK_DIFF);
 	if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
@@ -245,7 +247,6 @@
 		}
 	}
 
-	bsize = min(walk->walk_blocksize, n);
 	n = scatterwalk_clamp(&walk->in, n);
 	n = scatterwalk_clamp(&walk->out, n);