diff --git a/include/mbedtls/chacha20.h b/include/mbedtls/chacha20.h
index a2856a7..f88bd28 100644
--- a/include/mbedtls/chacha20.h
+++ b/include/mbedtls/chacha20.h
@@ -36,6 +36,10 @@
 
 #define MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA -0x003B /**< Invalid input parameter(s). */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #if !defined(MBEDTLS_CHACHA20_ALT)
 
 typedef struct
@@ -189,4 +193,8 @@
  */
 int mbedtls_chacha20_self_test( int verbose );
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* MBEDTLS_CHACHA20_H */