diff --git a/src/runtime/mheap.go b/src/runtime/mheap.go
index af14bf58a3a..be53f7bd91e 100644
--- a/src/runtime/mheap.go
+++ b/src/runtime/mheap.go
@@ -200,7 +200,7 @@ type mheap struct {
 	// central is indexed by spanClass.
 	central [numSpanClasses]struct {
 		mcentral mcentral
-		pad      [cpu.CacheLinePadSize - unsafe.Sizeof(mcentral{})%cpu.CacheLinePadSize]byte
+		pad      [(cpu.CacheLinePadSize - unsafe.Sizeof(mcentral{})%cpu.CacheLinePadSize) % cpu.CacheLinePadSize]byte
 	}
 
 	spanalloc             fixalloc // allocator for span*
diff --git a/src/runtime/stack.go b/src/runtime/stack.go
index b94a4a7249e..22dc2d4748d 100644
--- a/src/runtime/stack.go
+++ b/src/runtime/stack.go
@@ -157,7 +157,7 @@ const (
 // There is a free list for each order.
 var stackpool [_NumStackOrders]struct {
 	item stackpoolItem
-	_    [cpu.CacheLinePadSize - unsafe.Sizeof(stackpoolItem{})%cpu.CacheLinePadSize]byte
+	_    [(cpu.CacheLinePadSize - unsafe.Sizeof(stackpoolItem{})%cpu.CacheLinePadSize) % cpu.CacheLinePadSize]byte
 }
 
 type stackpoolItem struct {