diff --git a/ractor.c b/ractor.c
index d6559dfc2a..3c05964e91 100644
--- a/ractor.c
+++ b/ractor.c
@@ -545,7 +545,7 @@ ractor_sleep_interrupt(void *ptr)
     RACTOR_UNLOCK(r);
 }
 
-#if USE_RUBY_DEBUG_LOG
+#if defined(USE_RUBY_DEBUG_LOG) && USE_RUBY_DEBUG_LOG
 static const char *
 wait_status_str(enum ractor_wait_status wait_status)
 {
diff --git a/transient_heap.c b/transient_heap.c
index c14cf14613..c3df263491 100644
--- a/transient_heap.c
+++ b/transient_heap.c
@@ -748,7 +748,7 @@ transient_heap_block_evacuate(struct transient_heap* theap, struct transient_hea
     }
 }
 
-#if USE_RUBY_DEBUG_LOG
+#if defined(USE_RUBY_DEBUG_LOG) && USE_RUBY_DEBUG_LOG
 static const char *
 transient_heap_status_cstr(enum transient_heap_status status)
 {
diff --git a/vm_debug.h b/vm_debug.h
index fa70de334d..803a7ccf4b 100644
--- a/vm_debug.h
+++ b/vm_debug.h
@@ -101,7 +101,7 @@ bool ruby_debug_log_filter(const char *func_name);
 // You can use this macro for temporary usage (you should not commit it).
 #define _RUBY_DEBUG_LOG(...) ruby_debug_log(__FILE__, __LINE__, RUBY_FUNCTION_NAME_STRING, "" __VA_ARGS__)
 
-#if USE_RUBY_DEBUG_LOG
+#if defined(USE_RUBY_DEBUG_LOG) && USE_RUBY_DEBUG_LOG
 # define RUBY_DEBUG_LOG_ENABLED(func_name) \
     (ruby_debug_log_mode && ruby_debug_log_filter(func_name))
 
diff --git a/vm_sync.h b/vm_sync.h
index 4d83b5e52c..0969e5bfc9 100644
--- a/vm_sync.h
+++ b/vm_sync.h
@@ -4,7 +4,7 @@
 #include "vm_debug.h"
 #include "debug_counter.h"
 
-#if USE_RUBY_DEBUG_LOG
+#if defined(USE_RUBY_DEBUG_LOG) && USE_RUBY_DEBUG_LOG
 #define LOCATION_ARGS const char *file, int line
 #define LOCATION_PARAMS file, line
 #define APPEND_LOCATION_ARGS , const char *file, int line