diff --git a/crypto/mem_clr.c b/crypto/mem_clr.c
index 3df1f3928d06881630978c8a688ede833f39fe4c..1a06636d0ce8da052d0dec9580362274208084fb 100644
--- a/crypto/mem_clr.c
+++ b/crypto/mem_clr.c
@@ -66,6 +66,10 @@ void OPENSSL_cleanse(void *ptr, size_t len)
 {
     unsigned char *p = ptr;
     size_t loop = len, ctr = cleanse_ctr;
+
+    if (ptr == NULL)
+        return;
+
     while (loop--) {
         *(p++) = (unsigned char)ctr;
         ctr += (17 + ((size_t)p & 0xF));