diff --git a/src/cmd/compile/internal/gc/fmt.go b/src/cmd/compile/internal/gc/fmt.go
index 0f4b6c9936..16b81e6a88 100644
--- a/src/cmd/compile/internal/gc/fmt.go
+++ b/src/cmd/compile/internal/gc/fmt.go
@@ -1114,6 +1114,7 @@ var opprec = []int{
 	OSLICEARR:     8,
 	OSLICE3:       8,
 	OSLICE3ARR:    8,
+	OSLICEHEADER:  8,
 	ODOTINTER:     8,
 	ODOTMETH:      8,
 	ODOTPTR:       8,
@@ -1393,6 +1394,12 @@ func (n *Node) exprfmt(s fmt.State, prec int, mode fmtMode) {
 		}
 		fmt.Fprint(s, "]")
 
+	case OSLICEHEADER:
+		if n.List.Len() != 2 {
+			Fatalf("bad OSLICEHEADER list length %d", n.List.Len())
+		}
+		mode.Fprintf(s, "sliceheader{%v,%v,%v}", n.Left, n.List.First(), n.List.Second())
+
 	case OCOPY, OCOMPLEX:
 		mode.Fprintf(s, "%#v(%v, %v)", n.Op, n.Left, n.Right)
 
diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go
index 8ec60cbbba..e6a8ed4bda 100644
--- a/src/cmd/compile/internal/gc/typecheck.go
+++ b/src/cmd/compile/internal/gc/typecheck.go
@@ -1160,11 +1160,15 @@ func typecheck1(n *Node, top int) (res *Node) {
 		ok |= Erv
 
 		t := n.Type
+		if t == nil {
+			Fatalf("no type specified for OSLICEHEADER")
+		}
+
 		if !t.IsSlice() {
 			Fatalf("invalid type %v for OSLICEHEADER", n.Type)
 		}
 
-		if !n.Left.Type.IsUnsafePtr() {
+		if n.Left == nil || n.Left.Type == nil || !n.Left.Type.IsUnsafePtr() {
 			Fatalf("need unsafe.Pointer for OSLICEHEADER")
 		}
 
diff --git a/src/cmd/compile/internal/gc/walk.go b/src/cmd/compile/internal/gc/walk.go
index f459cb3dec..fa0dcab5eb 100644
--- a/src/cmd/compile/internal/gc/walk.go
+++ b/src/cmd/compile/internal/gc/walk.go
@@ -1351,14 +1351,17 @@ opswitch:
 				argtype = types.Types[TINT]
 			}
 
+			m := nod(OSLICEHEADER, nil, nil)
+			m.Type = t
+
 			fn := syslook(fnname)
-			n.Left = mkcall1(fn, types.Types[TUNSAFEPTR], init, typename(t.Elem()), conv(len, argtype), conv(cap, argtype))
-			n.Left.SetNonNil(true)
-			n.List.Set2(conv(len, types.Types[TINT]), conv(cap, types.Types[TINT]))
-			n.Op = OSLICEHEADER
-			n.Type = t
-			n = typecheck(n, Erv)
-			n = walkexpr(n, init)
+			m.Left = mkcall1(fn, types.Types[TUNSAFEPTR], init, typename(t.Elem()), conv(len, argtype), conv(cap, argtype))
+			m.Left.SetNonNil(true)
+			m.List.Set2(conv(len, types.Types[TINT]), conv(cap, types.Types[TINT]))
+
+			m = typecheck(m, Erv)
+			m = walkexpr(m, init)
+			n = m
 		}
 
 	case ORUNESTR: