diff --git a/src/runtime/stack.go b/src/runtime/stack.go
index cdf859a7ff1342f39015018bceeb7cc5c4118066..d43c6ace4ffcf20e29eb7cbe1089493edd09b6b2 100644
--- a/src/runtime/stack.go
+++ b/src/runtime/stack.go
@@ -69,7 +69,7 @@ const (
 	// to each stack below the usual guard area for OS-specific
 	// purposes like signal handling. Used on Windows, Plan 9,
 	// and iOS because they do not use a separate stack.
-	stackSystem = goos.IsWindows*512*goarch.PtrSize + goos.IsPlan9*512 + goos.IsIos*goarch.IsArm64*1024
+	stackSystem = goos.IsWindows*4096 + goos.IsPlan9*512 + goos.IsIos*goarch.IsArm64*1024
 
 	// The minimum size of stack used by Go code
 	stackMin = 2048
@@ -1330,7 +1330,7 @@ func morestackc() {
 }
 
 // startingStackSize is the amount of stack that new goroutines start with.
-// It is a power of 2, and between _FixedStack and maxstacksize, inclusive.
+// It is a power of 2, and between fixedStack and maxstacksize, inclusive.
 // startingStackSize is updated every GC by tracking the average size of
 // stacks scanned during the GC.
 var startingStackSize uint32 = fixedStack