diff --git a/common.mk b/common.mk
index 220089c8a1..1dd266736d 100644
--- a/common.mk
+++ b/common.mk
@@ -4464,6 +4464,7 @@ encoding.$(OBJEXT): {$(VPATH)}backward/2/long_long.h
 encoding.$(OBJEXT): {$(VPATH)}backward/2/stdalign.h
 encoding.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 encoding.$(OBJEXT): {$(VPATH)}config.h
+encoding.$(OBJEXT): {$(VPATH)}debug_counter.h
 encoding.$(OBJEXT): {$(VPATH)}defines.h
 encoding.$(OBJEXT): {$(VPATH)}encindex.h
 encoding.$(OBJEXT): {$(VPATH)}encoding.c
@@ -4639,6 +4640,7 @@ enum.$(OBJEXT): $(top_srcdir)/internal/numeric.h
 enum.$(OBJEXT): $(top_srcdir)/internal/object.h
 enum.$(OBJEXT): $(top_srcdir)/internal/proc.h
 enum.$(OBJEXT): $(top_srcdir)/internal/rational.h
+enum.$(OBJEXT): $(top_srcdir)/internal/re.h
 enum.$(OBJEXT): $(top_srcdir)/internal/serial.h
 enum.$(OBJEXT): $(top_srcdir)/internal/static_assert.h
 enum.$(OBJEXT): $(top_srcdir)/internal/vm.h
@@ -13824,6 +13826,7 @@ symbol.$(OBJEXT): {$(VPATH)}backward/2/long_long.h
 symbol.$(OBJEXT): {$(VPATH)}backward/2/stdalign.h
 symbol.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 symbol.$(OBJEXT): {$(VPATH)}config.h
+symbol.$(OBJEXT): {$(VPATH)}debug_counter.h
 symbol.$(OBJEXT): {$(VPATH)}defines.h
 symbol.$(OBJEXT): {$(VPATH)}encoding.h
 symbol.$(OBJEXT): {$(VPATH)}gc.h
@@ -15953,6 +15956,7 @@ vm_sync.$(OBJEXT): {$(VPATH)}backward/2/stdalign.h
 vm_sync.$(OBJEXT): {$(VPATH)}backward/2/stdarg.h
 vm_sync.$(OBJEXT): {$(VPATH)}config.h
 vm_sync.$(OBJEXT): {$(VPATH)}constant.h
+vm_sync.$(OBJEXT): {$(VPATH)}debug_counter.h
 vm_sync.$(OBJEXT): {$(VPATH)}defines.h
 vm_sync.$(OBJEXT): {$(VPATH)}gc.h
 vm_sync.$(OBJEXT): {$(VPATH)}id.h
diff --git a/debug_counter.h b/debug_counter.h
index 0e13464d00..593d2f701d 100644
--- a/debug_counter.h
+++ b/debug_counter.h
@@ -322,6 +322,13 @@ RB_DEBUG_COUNTER(theap_alloc)
 RB_DEBUG_COUNTER(theap_alloc_fail)
 RB_DEBUG_COUNTER(theap_evacuate)
 
+// VM sync
+RB_DEBUG_COUNTER(vm_sync_lock)
+RB_DEBUG_COUNTER(vm_sync_lock_enter)
+RB_DEBUG_COUNTER(vm_sync_lock_enter_nb)
+RB_DEBUG_COUNTER(vm_sync_lock_enter_cr)
+RB_DEBUG_COUNTER(vm_sync_barrier)
+
 /* mjit_exec() counts */
 RB_DEBUG_COUNTER(mjit_exec)
 RB_DEBUG_COUNTER(mjit_exec_not_added)
diff --git a/vm_sync.c b/vm_sync.c
index 22c2299162..d2ce727202 100644
--- a/vm_sync.c
+++ b/vm_sync.c
@@ -228,6 +228,8 @@ vm_barrier_finish_p(rb_vm_t *vm)
 void
 rb_vm_barrier(void)
 {
+    RB_DEBUG_COUNTER_INC(vm_sync_barrier);
+
     if (!rb_multi_ractor_p()) {
         // no other ractors
         return;
diff --git a/vm_sync.h b/vm_sync.h
index 8712e1a1ca..b8ebb3bbc5 100644
--- a/vm_sync.h
+++ b/vm_sync.h
@@ -3,6 +3,7 @@
 #define RUBY_VM_SYNC_H
 
 #include "vm_debug.h"
+#include "debug_counter.h"
 
 #if USE_RUBY_DEBUG_LOG
 #define LOCATION_ARGS const char *file, int line
@@ -51,6 +52,8 @@ rb_multi_ractor_p(void)
 static inline void
 rb_vm_lock(const char *file, int line)
 {
+    RB_DEBUG_COUNTER_INC(vm_sync_lock);
+
     if (rb_multi_ractor_p()) {
         rb_vm_lock_body(LOCATION_PARAMS);
     }
@@ -67,6 +70,8 @@ rb_vm_unlock(const char *file, int line)
 static inline void
 rb_vm_lock_enter(unsigned int *lev, const char *file, int line)
 {
+    RB_DEBUG_COUNTER_INC(vm_sync_lock_enter);
+
     if (rb_multi_ractor_p()) {
         rb_vm_lock_enter_body(lev APPEND_LOCATION_PARAMS);
     }
@@ -75,6 +80,8 @@ rb_vm_lock_enter(unsigned int *lev, const char *file, int line)
 static inline void
 rb_vm_lock_enter_nb(unsigned int *lev, const char *file, int line)
 {
+    RB_DEBUG_COUNTER_INC(vm_sync_lock_enter_nb);
+
     if (rb_multi_ractor_p()) {
         rb_vm_lock_enter_body_nb(lev APPEND_LOCATION_PARAMS);
     }
@@ -91,6 +98,7 @@ rb_vm_lock_leave(unsigned int *lev, const char *file, int line)
 static inline void
 rb_vm_lock_enter_cr(struct rb_ractor_struct *cr, unsigned int *levp, const char *file, int line)
 {
+    RB_DEBUG_COUNTER_INC(vm_sync_lock_enter_cr);
     rb_vm_lock_enter_body_cr(cr, levp APPEND_LOCATION_PARAMS);
 }