diff --git a/library/ecdh_misc.h b/library/ecdh_misc.h
new file mode 100644
index 0000000..3d75b0f
--- /dev/null
+++ b/library/ecdh_misc.h
@@ -0,0 +1,41 @@
+/**
+ * \file ecdh_misc.h
+ *
+ * \brief Internal functions shared by the ECDH module
+ */
+/*
+ *  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.
+ */
+#if !defined(MBEDTLS_ECDH_MISC_H)
+#define MBEDTLS_ECDH_MISC_H
+
+#if defined(MBEDTLS_ECDH_C)
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
+
+/*
+ * TLS 1.3 version of mbedtls_ecdh_make_params in ecdh.h
+ */
+int mbedtls_ecdh_tls13_make_params( mbedtls_ecdh_context *ctx, size_t *olen,
+                                    unsigned char *buf, size_t blen,
+                                    int ( *f_rng )( void *, unsigned char *, size_t ),
+                                    void *p_rng );
+
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
+
+#endif /* MBEDTLS_ECDH_C */
+
+#endif /* !MBEDTLS_ECDH_MISC_H */