diff --git a/src/ssl.c b/src/ssl.c
index 38a94b1e7..e3ebdd3a7 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -567,13 +567,13 @@ word16 CyaSSL_SNI_GetRequest(CYASSL* ssl, byte type, void** data)
 #endif /* HAVE_SNI */
 
 
-#ifdef MAX_FRAGMENT_LENGTH
+#ifdef HAVE_MAX_FRAGMENT
 int CyaSSL_UseMaxFragment(CYASSL* ssl, byte mfl)
 {
     if (ssl == NULL)
         return BAD_FUNC_ARG;
 
-    return TLSX_UseMaxFragment(ssl->extensions, mfl);
+    return TLSX_UseMaxFragment(&ssl->extensions, mfl);
 }
 
 int CyaSSL_CTX_UseMaxFragment(CYASSL_CTX* ctx, byte mfl)
@@ -581,7 +581,7 @@ int CyaSSL_CTX_UseMaxFragment(CYASSL_CTX* ctx, byte mfl)
     if (ctx == NULL)
         return BAD_FUNC_ARG;
 
-    return TLSX_UseMaxFragment(ctx->extensions, mfl);
+    return TLSX_UseMaxFragment(&ctx->extensions, mfl);
 }
 #endif /* HAVE_MAX_FRAGMENT */
 
diff --git a/src/tls.c b/src/tls.c
index 07575a8fb..cc8e51069 100644
--- a/src/tls.c
+++ b/src/tls.c
@@ -905,14 +905,14 @@ int TLSX_UseMaxFragment(TLSX** extensions, byte mfl)
     if (extensions == NULL)
         return BAD_FUNC_ARG;
 
-    if (CYASSL_MFL_2_9 <= mfl && mfl <= CYASSL_MFL_2_12) {
-        if ((data = XMALLOC(ENUM_LEN, 0, DYNAMIC_TYPE_TLSX)) == NULL)
-            return MEMORY_E;
-
-        data[0] = mfl;
-    } else
+    if (mfl < CYASSL_MFL_2_9 || CYASSL_MFL_2_13 < mfl)
         return BAD_FUNC_ARG;
 
+    if ((data = XMALLOC(ENUM_LEN, 0, DYNAMIC_TYPE_TLSX)) == NULL)
+        return MEMORY_E;
+
+    data[0] = mfl;
+
     /* push new MFL extension. */
     if ((ret = TLSX_Append(extensions, MAX_FRAGMENT_LENGTH)) != 0) {
         XFREE(data, 0, DYNAMIC_TYPE_TLSX);
diff --git a/tests/api.c b/tests/api.c
index 8cd10d5f4..1e3f0be95 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -50,8 +50,11 @@ static int test_CyaSSL_read_write(void);
 #ifdef HAVE_TLS_EXTENSIONS
 #ifdef HAVE_SNI
 static void test_CyaSSL_UseSNI(void);
-#endif /* HAVE_TLS_EXTENSIONS */
 #endif /* HAVE_SNI */
+#ifdef HAVE_MAX_FRAGMENT
+static void test_CyaSSL_UseMaxFragment(void);
+#endif /* HAVE_MAX_FRAGMENT */
+#endif /* HAVE_TLS_EXTENSIONS */
 
 /* test function helpers */
 static int test_method(CYASSL_METHOD *method, const char *name);
@@ -107,6 +110,9 @@ int ApiTest(void)
 #ifdef HAVE_SNI
     test_CyaSSL_UseSNI();
 #endif /* HAVE_SNI */
+#ifdef HAVE_MAX_FRAGMENT
+    test_CyaSSL_UseMaxFragment();
+#endif /* HAVE_MAX_FRAGMENT */
 #endif /* HAVE_TLS_EXTENSIONS */
     test_CyaSSL_Cleanup();
     printf(" End API Tests\n");
@@ -382,9 +388,43 @@ void test_CyaSSL_UseSNI(void)
     server_callbacks.on_result = verify_SNI_fake_matching;
 
     test_CyaSSL_client_server(&client_callbacks, &server_callbacks);
-
 }
 #endif /* HAVE_SNI */
+
+#ifdef HAVE_MAX_FRAGMENT
+static void test_CyaSSL_UseMaxFragment(void)
+{
+    CYASSL_CTX *ctx = CyaSSL_CTX_new(CyaSSLv23_client_method());
+    CYASSL     *ssl = CyaSSL_new(ctx);
+
+    AssertNotNull(ctx);
+    AssertNotNull(ssl);
+
+    /* error cases */
+    AssertIntNE(0, CyaSSL_CTX_UseMaxFragment(NULL, CYASSL_MFL_2_9));
+    AssertIntNE(0, CyaSSL_UseMaxFragment(    NULL, CYASSL_MFL_2_9));
+    AssertIntNE(0, CyaSSL_CTX_UseMaxFragment(ctx, 0));
+    AssertIntNE(0, CyaSSL_CTX_UseMaxFragment(ctx, 6));
+    AssertIntNE(0, CyaSSL_UseMaxFragment(ssl, 0));
+    AssertIntNE(0, CyaSSL_UseMaxFragment(ssl, 6));
+
+    /* success case */
+    AssertIntEQ(0, CyaSSL_CTX_UseMaxFragment(ctx,  CYASSL_MFL_2_9));
+    AssertIntEQ(0, CyaSSL_CTX_UseMaxFragment(ctx,  CYASSL_MFL_2_10));
+    AssertIntEQ(0, CyaSSL_CTX_UseMaxFragment(ctx,  CYASSL_MFL_2_11));
+    AssertIntEQ(0, CyaSSL_CTX_UseMaxFragment(ctx,  CYASSL_MFL_2_12));
+    AssertIntEQ(0, CyaSSL_CTX_UseMaxFragment(ctx,  CYASSL_MFL_2_13));
+    AssertIntEQ(0, CyaSSL_UseMaxFragment(    ssl,  CYASSL_MFL_2_9));
+    AssertIntEQ(0, CyaSSL_UseMaxFragment(    ssl,  CYASSL_MFL_2_10));
+    AssertIntEQ(0, CyaSSL_UseMaxFragment(    ssl,  CYASSL_MFL_2_11));
+    AssertIntEQ(0, CyaSSL_UseMaxFragment(    ssl,  CYASSL_MFL_2_12));
+    AssertIntEQ(0, CyaSSL_UseMaxFragment(    ssl,  CYASSL_MFL_2_13));
+
+    CyaSSL_free(ssl);
+    CyaSSL_CTX_free(ctx);
+}
+#endif /* HAVE_MAX_FRAGMENT */
+
 #endif /* HAVE_TLS_EXTENSIONS */
 
 #if !defined(NO_FILESYSTEM) && !defined(NO_CERTS)