diff --git a/crypto/buffer/buffer.c b/crypto/buffer/buffer.c
index a16f3bd342631951ac4d616ff87c482f3c192bf7..1c76d662a65b0e8680d52beb9a4cb80dfa4ea9cd 100644
--- a/crypto/buffer/buffer.c
+++ b/crypto/buffer/buffer.c
@@ -128,7 +128,8 @@ size_t BUF_MEM_grow(BUF_MEM *str, size_t len)
         return (len);
     }
     if (str->max >= len) {
-        memset(&str->data[str->length], 0, len - str->length);
+        if (str->data != NULL)
+            memset(&str->data[str->length], 0, len - str->length);
         str->length = len;
         return (len);
     }
@@ -160,7 +161,8 @@ size_t BUF_MEM_grow_clean(BUF_MEM *str, size_t len)
     size_t n;
 
     if (str->length >= len) {
-        memset(&str->data[len], 0, str->length - len);
+        if (str->data != NULL)
+            memset(&str->data[len], 0, str->length - len);
         str->length = len;
         return (len);
     }