diff --git a/include/mbedtls/chacha20.h b/include/mbedtls/chacha20.h
index 47bd7d3..cfea40a 100644
--- a/include/mbedtls/chacha20.h
+++ b/include/mbedtls/chacha20.h
@@ -52,7 +52,7 @@
 
 #if !defined(MBEDTLS_CHACHA20_ALT)
 
-typedef struct
+typedef struct mbedtls_chacha20_context
 {
     uint32_t state[16];          /*! The state (before round operations). */
     uint8_t  keystream8[64];     /*! Leftover keystream bytes. */