diff --git a/tests/configs/user-config-malloc-0-null.h b/tests/configs/user-config-malloc-0-null.h
new file mode 100644
index 0000000..226f4d1
--- /dev/null
+++ b/tests/configs/user-config-malloc-0-null.h
@@ -0,0 +1,34 @@
+/* mbedtls_config.h modifier that forces calloc(0) to return NULL.
+ * Used for testing.
+ */
+/*
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <stdlib.h>
+
+#ifndef MBEDTLS_PLATFORM_STD_CALLOC
+static inline void *custom_calloc(size_t nmemb, size_t size)
+{
+    if (nmemb == 0 || size == 0) {
+        return NULL;
+    }
+    return calloc(nmemb, size);
+}
+
+#define MBEDTLS_PLATFORM_MEMORY
+#define MBEDTLS_PLATFORM_STD_CALLOC custom_calloc
+#endif