diff --git a/thread.c b/thread.c
index fa14f28cbb..2d978408f2 100644
--- a/thread.c
+++ b/thread.c
@@ -97,9 +97,9 @@ static void set_unblock_function(rb_thread_t *th, rb_unblock_function_t *func, v
 				 struct rb_unblock_callback *old);
 static void reset_unblock_function(rb_thread_t *th, const struct rb_unblock_callback *old);
 
-static void inline blocking_region_begin(rb_thread_t *th, struct rb_blocking_region_buffer *region,
+static inline void blocking_region_begin(rb_thread_t *th, struct rb_blocking_region_buffer *region,
 					 rb_unblock_function_t *func, void *arg);
-static void inline blocking_region_end(rb_thread_t *th, struct rb_blocking_region_buffer *region);
+static inline void blocking_region_end(rb_thread_t *th, struct rb_blocking_region_buffer *region);
 
 #define GVL_UNLOCK_BEGIN() do { \
   rb_thread_t *_th_stored = GET_THREAD(); \