diff --git a/src/bio.c b/src/bio.c
index 921f3d496..c7fa37b14 100644
--- a/src/bio.c
+++ b/src/bio.c
@@ -2537,7 +2537,7 @@ int wolfSSL_BIO_flush(WOLFSSL_BIO* bio)
             len = (int)XSTRLEN((const char*)buf) + 1;
         }
 
-        if (wolfSSL_BUF_MEM_resize(bio->mem_buf, len) == 0) {
+        if (len > 0 && wolfSSL_BUF_MEM_resize(bio->mem_buf, len) == 0) {
             wolfSSL_BIO_free(bio);
             return NULL;
         }
diff --git a/tests/api.c b/tests/api.c
index a0e09adf6..d17e5b5ea 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -39123,6 +39123,9 @@ static void test_wolfSSL_BIO_write(void)
     BIO_set_retry_read(bio);
     BIO_free_all(bio); /* frees bio64s also */
 
+    AssertNotNull(bio = BIO_new_mem_buf(out, 0));
+    AssertIntEQ(BIO_write(bio, msg, sizeof(msg)), sizeof(msg));
+    BIO_free(bio);
     printf(resultFmt, passed);
     #endif
 }