diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index d182ed62dc..3a0588216e 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -420,7 +420,7 @@ func mHeap_SysAlloc(h *mheap, n uintptr) unsafe.Pointer {
 		sysMap((unsafe.Pointer)(p), n, h.arena_reserved, &memstats.heap_sys)
 		mHeap_MapBits(h, p+n)
 		mHeap_MapSpans(h, p+n)
-		h.arena_used = p+n
+		h.arena_used = p + n
 		if raceenabled {
 			racemapshadow((unsafe.Pointer)(p), n)
 		}
@@ -456,7 +456,7 @@ func mHeap_SysAlloc(h *mheap, n uintptr) unsafe.Pointer {
 	if uintptr(p)+n > uintptr(h.arena_used) {
 		mHeap_MapBits(h, p+n)
 		mHeap_MapSpans(h, p+n)
-		h.arena_used = p+n
+		h.arena_used = p + n
 		if p_end > h.arena_end {
 			h.arena_end = p_end
 		}