diff --git a/core/tiny_alloc_fast.inc.h b/core/tiny_alloc_fast.inc.h
index 44caa8a9..92e590cc 100644
--- a/core/tiny_alloc_fast.inc.h
+++ b/core/tiny_alloc_fast.inc.h
@@ -726,6 +726,7 @@ static inline void* tiny_alloc_fast(size_t size) {
     // Note: ACE learning preserved (HAKMEM's differentiator vs mimalloc)
 
     // Debug: Check if Ultra SLIM is enabled (first call only)
+#if !HAKMEM_BUILD_RELEASE
     static __thread int debug_checked = 0;
     if (!debug_checked) {
         int enabled = ultra_slim_mode_enabled();
@@ -736,6 +737,7 @@ static inline void* tiny_alloc_fast(size_t size) {
         }
         debug_checked = 1;
     }
+#endif
 
     if (__builtin_expect(ultra_slim_mode_enabled(), 0)) {
         return ultra_slim_alloc_with_refill(size);