diff --git a/src/runtime/mcentral.go b/src/runtime/mcentral.go
index 9ca8e5d222..baede31405 100644
--- a/src/runtime/mcentral.go
+++ b/src/runtime/mcentral.go
@@ -244,7 +244,7 @@ func (c *mcentral) freeSpan(s *mspan, preserve bool, wasempty bool) bool {
 
 	c.nonempty.remove(s)
 	unlock(&c.lock)
-	mheap_.freeSpan(s, 0)
+	mheap_.freeSpan(s, false)
 	return true
 }
 
diff --git a/src/runtime/mgcsweep.go b/src/runtime/mgcsweep.go
index 00950aede2..104bd868fa 100644
--- a/src/runtime/mgcsweep.go
+++ b/src/runtime/mgcsweep.go
@@ -366,7 +366,7 @@ func (s *mspan) sweep(preserve bool) bool {
 			s.limit = 0 // prevent mlookup from finding this span
 			sysFault(unsafe.Pointer(s.base()), size)
 		} else {
-			mheap_.freeSpan(s, 1)
+			mheap_.freeSpan(s, true)
 		}
 		c.local_nlargefree++
 		c.local_largefree += size
diff --git a/src/runtime/mheap.go b/src/runtime/mheap.go
index 1d672cdf21..48b3f5364a 100644
--- a/src/runtime/mheap.go
+++ b/src/runtime/mheap.go
@@ -945,7 +945,10 @@ func (h *mheap) grow(npage uintptr) bool {
 }
 
 // Free the span back into the heap.
-func (h *mheap) freeSpan(s *mspan, acct int32) {
+//
+// large must match the value of large passed to mheap.alloc. This is
+// used for accounting.
+func (h *mheap) freeSpan(s *mspan, large bool) {
 	systemstack(func() {
 		mp := getg().m
 		lock(&h.lock)
@@ -959,7 +962,8 @@ func (h *mheap) freeSpan(s *mspan, acct int32) {
 			bytes := s.npages << _PageShift
 			msanfree(base, bytes)
 		}
-		if acct != 0 {
+		if large {
+			// Match accounting done in mheap.alloc.
 			memstats.heap_objects--
 		}
 		if gcBlackenEnabled != 0 {