diff --git a/src/threadpool-atomics.h b/src/threadpool-atomics.h
index 67d4870..3eb24b1 100644
--- a/src/threadpool-atomics.h
+++ b/src/threadpool-atomics.h
@@ -308,7 +308,7 @@ static inline int32_t pthreadpool_fetch_add_sequentially_consistent_int32_t(
   return atomic_fetch_add_explicit(address, value, memory_order_seq_cst);
 }
 
-static inline int32_t pthreadpool_fetch_add_sequentially_consistent_uint32_t(
+static inline uint32_t pthreadpool_fetch_add_sequentially_consistent_uint32_t(
     pthreadpool_atomic_uint32_t* address, uint32_t value) {
   return atomic_fetch_add_explicit(address, value, memory_order_seq_cst);
 }