diff --git a/crypto/drbg.c b/crypto/drbg.c
index b69409cb7e6ac70b6d9ae4c19c469ad7abb684e6..8d2944fab8e84f4e484a1478aac1c16206914938 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -487,7 +487,7 @@ static int drbg_ctr_df(struct drbg_state *drbg,
 
 out:
 	memset(iv, 0, drbg_blocklen(drbg));
-	memset(temp, 0, drbg_statelen(drbg));
+	memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg));
 	memset(pad, 0, drbg_blocklen(drbg));
 	return ret;
 }