diff --git a/include/asterisk/lock.h b/include/asterisk/lock.h
index 904a7e64ec3183cb91ef539c0bd119ad488b7d86..db85c497be585a8e57b90ae91b975ce4a443de7d 100644
--- a/include/asterisk/lock.h
+++ b/include/asterisk/lock.h
@@ -782,6 +782,8 @@ AST_INLINE_API(int ast_atomic_dec_and_test(volatile int *p),
 #define ast_channel_trylock(x)		ast_mutex_trylock(&x->lock)
 #else
 
+struct ast_channel;
+
 /*! \brief Lock AST channel (and print debugging output)
 \note You need to enable DEBUG_CHANNEL_LOCKS for this function */
 int ast_channel_lock(struct ast_channel *chan);