diff --git a/src/runtime/heapdump.go b/src/runtime/heapdump.go
index 992df6391e..4d55b316f7 100644
--- a/src/runtime/heapdump.go
+++ b/src/runtime/heapdump.go
@@ -371,7 +371,12 @@ func dumpgoroutine(gp *g) {
 		dumpint(uint64(d.sp))
 		dumpint(uint64(d.pc))
 		dumpint(uint64(uintptr(unsafe.Pointer(d.fn))))
-		dumpint(uint64(uintptr(unsafe.Pointer(d.fn.fn))))
+		if d.fn == nil {
+			// d.fn can be nil for open-coded defers
+			dumpint(uint64(0))
+		} else {
+			dumpint(uint64(uintptr(unsafe.Pointer(d.fn.fn))))
+		}
 		dumpint(uint64(uintptr(unsafe.Pointer(d.link))))
 	}
 	for p := gp._panic; p != nil; p = p.link {
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index eecc6a78ac..c319196557 100644
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -824,10 +824,10 @@ type _defer struct {
 	// defers. We have only one defer record for the entire frame (which may
 	// currently have 0, 1, or more defers active).
 	openDefer bool
-	sp        uintptr // sp at time of defer
-	pc        uintptr // pc at time of defer
-	fn        *funcval
-	_panic    *_panic // panic that is running defer
+	sp        uintptr  // sp at time of defer
+	pc        uintptr  // pc at time of defer
+	fn        *funcval // can be nil for open-coded defers
+	_panic    *_panic  // panic that is running defer
 	link      *_defer
 
 	// If openDefer is true, the fields below record values about the stack