diff --git a/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp b/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
index c26fb98273b..789ee740bec 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.cpp
@@ -2467,18 +2467,19 @@ void ShenandoahHeap::unpin_object(JavaThread* thr, oop o) {
 }
 
 void ShenandoahHeap::flush_region_pin_cache(JavaThread* thr) {
+  size_t reg_idx_cached = ShenandoahThreadLocalData::pin_cache_region(thr);
   size_t count = ShenandoahThreadLocalData::pin_cache_count(thr);
   if (count != 0) {
-    get_region(ShenandoahThreadLocalData::pin_cache_region(thr))->inc_pin_count(count);
+    get_region(reg_idx_cached)->inc_pin_count(count);
   }
   ShenandoahThreadLocalData::pin_cache_set_region(thr, SIZE_MAX);
   ShenandoahThreadLocalData::pin_cache_set_count(thr, 0);
 }
 
 void ShenandoahHeap::flush_region_pin_cache() {
-  assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint.");
-  for (JavaThreadIteratorWithHandle jtiwh; JavaThread *thread = jtiwh.next(); ) {
-    flush_region_pin_cache(thread);
+  assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint");
+  for (JavaThreadIteratorWithHandle jtiwh; JavaThread *t = jtiwh.next(); ) {
+    flush_region_pin_cache(t);
   }
 }
 
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp b/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp
index d297f6bf5e3..5cd7eeab999 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp
@@ -686,9 +686,11 @@ public:
   void pin_object(JavaThread* thread, oop obj) override;
   void unpin_object(JavaThread* thread, oop obj) override;
 
-  // Updates each region's pin counts from the per-thread caches and resets them.
-  // Must be called before any decision based on pin counts.
+  // Flushes this thread's current pin count to its region's shared counter
+  // and resets the pin cache.
   void flush_region_pin_cache(JavaThread* thread);
+
+  // Flushes all Java threads' pin counts.
   void flush_region_pin_cache();
 
   void sync_pinned_region_status();
diff --git a/src/hotspot/share/gc/shenandoah/shenandoahThreadLocalData.hpp b/src/hotspot/share/gc/shenandoah/shenandoahThreadLocalData.hpp
index 3fc97c38997..da8f060db6e 100644
--- a/src/hotspot/share/gc/shenandoah/shenandoahThreadLocalData.hpp
+++ b/src/hotspot/share/gc/shenandoah/shenandoahThreadLocalData.hpp
@@ -257,8 +257,8 @@ public:
     return data(thread)->_pin_count;
   }
 
-  static void pin_cache_set_region(Thread* thread, size_t reg_idx_pin) {
-    data(thread)->_pin_region_idx = reg_idx_pin;
+  static void pin_cache_set_region(Thread* thread, size_t region_idx) {
+    data(thread)->_pin_region_idx = region_idx;
   }
 
   static void pin_cache_set_count(Thread* thread, size_t new_count) {