diff --git a/crypto/crypto_utils.c b/crypto/crypto_utils.c
index f154424..b159ed2 100644
--- a/crypto/crypto_utils.c
+++ b/crypto/crypto_utils.c
@@ -138,7 +138,7 @@ init_sha256(void)
 }
 
 /*
- * Check is either the given checksum name or id is valid and
+ * Check if either the given checksum name or id is valid and
  * return it's properties.
  */
 int
diff --git a/rabin/rabin_dedup.c b/rabin/rabin_dedup.c
index ad32df8..fd0790a 100755
--- a/rabin/rabin_dedup.c
+++ b/rabin/rabin_dedup.c
@@ -179,7 +179,7 @@ create_dedupe_context(uint64_t chunksize, uint64_t real_chunksize, int rab_blk_s
 
 	ctx->fixed_flag = fixed_flag;
 	ctx->rabin_break_patt = 0;
-	ctx->rabin_poly_avg_block_size = 1 << (rab_blk_sz + RAB_BLK_MIN_BITS);
+	ctx->rabin_poly_avg_block_size = RAB_BLK_AVG_SZ(rab_blk_sz);
 	ctx->rabin_avg_block_mask = RAB_BLK_MASK;
 	ctx->rabin_poly_min_block_size = dedupe_min_blksz(rab_blk_sz);
 	ctx->delta_flag = 0;
diff --git a/rabin/rabin_dedup.h b/rabin/rabin_dedup.h
index 7aab87f..d98aeb6 100644
--- a/rabin/rabin_dedup.h
+++ b/rabin/rabin_dedup.h
@@ -74,6 +74,7 @@
 #define	RAB_POLYNOMIAL_MAX_WIN_SIZE 64
 #define	RAB_POLYNOMIAL_MAX_BLOCK_SIZE (128 * 1024)
 #define	RAB_BLK_MASK (((1 << RAB_BLK_MIN_BITS) - 1) >> 1)
+#define	RAB_BLK_AVG_SZ(x) (1 << ((x) + RAB_BLK_MIN_BITS))
 
 // Minimum practical chunk size when doing dedup
 #define	RAB_MIN_CHUNK_SIZE (1048576L)