diff --git a/src/ssl.c b/src/ssl.c
index 255ec7cc8..95e228442 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -14913,7 +14913,7 @@ int wolfSSL_set_compression(WOLFSSL* ssl)
     {
         WOLFSSL_BIO* bio = NULL;
 
-        if (buf == NULL || len < 0) {
+        if (buf == NULL) {
             return bio;
         }
 
@@ -14922,6 +14922,9 @@ int wolfSSL_set_compression(WOLFSSL* ssl)
             return bio;
         }
 
+        if (len < 0) {
+            len = XSTRLEN(buf);
+        }
         bio->num = bio->wrSz = len;
         bio->ptr = (byte*)XMALLOC(len, 0, DYNAMIC_TYPE_OPENSSL);
         if (bio->ptr == NULL) {
diff --git a/tests/api.c b/tests/api.c
index c230c3c4a..507d59116 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -24983,10 +24983,9 @@ static void test_wolfSSL_BIO_gets(void)
 
     /* try with bad args */
     AssertNull(bio = BIO_new_mem_buf(NULL, sizeof(msg)));
-    AssertNull(bio = BIO_new_mem_buf((void*)msg, -1));
 
     /* try with real msg */
-    AssertNotNull(bio = BIO_new_mem_buf((void*)msg, sizeof(msg)));
+    AssertNotNull(bio = BIO_new_mem_buf((void*)msg, -1));
     XMEMSET(bio_buffer, 0, bufferSz);
     AssertNotNull(BIO_push(bio, BIO_new(BIO_s_bio())));
     AssertNull(bio2 = BIO_find_type(bio, BIO_TYPE_FILE));