diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index 3d01ac517137c..b40045e4a5b36 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -514,6 +514,7 @@ type m struct {
 	g0      *g     // goroutine with scheduling stack
 	morebuf gobuf  // gobuf arg to morestack
 	divmod  uint32 // div/mod denominator for arm - known to liblink
+	_       uint32 // align next field to 8 bytes
 
 	// Fields not known to debuggers.
 	procid        uint64            // for debuggers, but offset not hard-coded