diff --git a/features/frameworks/greentea-client/greentea-client/test_env_c.h b/features/frameworks/greentea-client/greentea-client/test_env_c.h
new file mode 100644
index 0000000000..fd9754c65e
--- /dev/null
+++ b/features/frameworks/greentea-client/greentea-client/test_env_c.h
@@ -0,0 +1,33 @@
+/** \addtogroup frameworks */
+/** @{*/
+/*
+ * Copyright (c) 2013-2017, ARM Limited, All Rights Reserved
+ * 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.
+ */
+
+#ifndef TEST_ENV_C_H
+#define TEST_ENV_C_H
+
+
+/**
+ *  Greentea-client C API for communication with host side
+ */
+void GREENTEA_SETUP_C(const int timeout, const char * host_test);
+void greentea_send_kv_c(const char * key, const char * val);
+int greentea_parse_kv_c(char * key, char * val,
+                        const int key_len, const int val_len);
+
+#endif /* TEST_ENV_C_H */
+
diff --git a/features/frameworks/greentea-client/source/greentea_test_env_c.cpp b/features/frameworks/greentea-client/source/greentea_test_env_c.cpp
new file mode 100644
index 0000000000..3bf9f873c3
--- /dev/null
+++ b/features/frameworks/greentea-client/source/greentea_test_env_c.cpp
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2013-2017, ARM Limited, All Rights Reserved
+ * 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 "greentea-client/test_env.h"
+
+
+/**
+ *   C extensions of greentea client API.
+ *
+ *   NOTE: Added to support mbed-tls tests generated in C. Please enable more API if needed.
+ */
+
+extern "C" void GREENTEA_SETUP_C(const int timeout, const char * host_test){
+    GREENTEA_SETUP(timeout, host_test);
+};
+
+extern "C" void greentea_send_kv_c(const char * key, const char * val){
+    greentea_send_kv(key, val);
+};
+
+extern "C" int greentea_parse_kv_c(char * key, char * val,
+                                   const int key_len, const int val_len){
+    return greentea_parse_kv(key, val, key_len, val_len);
+};
+