diff --git a/ractor.c b/ractor.c
index 0306736c18..0eddc165fa 100644
--- a/ractor.c
+++ b/ractor.c
@@ -74,7 +74,9 @@ static void
 ractor_lock_self(rb_ractor_t *cr, const char *file, int line)
 {
     VM_ASSERT(cr == GET_RACTOR());
+#if RACTOR_CHECK_MODE > 0
     VM_ASSERT(cr->sync.locked_by != cr->pub.self);
+#endif
     ractor_lock(cr, file, line);
 }
 
@@ -94,7 +96,9 @@ static void
 ractor_unlock_self(rb_ractor_t *cr, const char *file, int line)
 {
     VM_ASSERT(cr == GET_RACTOR());
+#if RACTOR_CHECK_MODE > 0
     VM_ASSERT(cr->sync.locked_by == cr->pub.self);
+#endif
     ractor_unlock(cr, file, line);
 }
 
diff --git a/ractor_core.h b/ractor_core.h
index 412971decf..a065f5f809 100644
--- a/ractor_core.h
+++ b/ractor_core.h
@@ -5,7 +5,7 @@
 #include "vm_debug.h"
 
 #ifndef RACTOR_CHECK_MODE
-#define RACTOR_CHECK_MODE (0 || VM_CHECK_MODE || RUBY_DEBUG)
+#define RACTOR_CHECK_MODE (VM_CHECK_MODE || RUBY_DEBUG) && (SIZEOF_UINT64_T == SIZEOF_VALUE)
 #endif
 
 enum rb_ractor_basket_type {