diff --git a/misc/cgo/test/cgo_test.go b/misc/cgo/test/cgo_test.go
index 85f00a36533..b745a4417f1 100644
--- a/misc/cgo/test/cgo_test.go
+++ b/misc/cgo/test/cgo_test.go
@@ -58,6 +58,7 @@ func Test27660(t *testing.T)                 { test27660(t) }
 func Test28896(t *testing.T)                 { test28896(t) }
 func Test30065(t *testing.T)                 { test30065(t) }
 func Test32579(t *testing.T)                 { test32579(t) }
+func Test31891(t *testing.T)                 { test31891(t) }
 func TestAlign(t *testing.T)                 { testAlign(t) }
 func TestAtol(t *testing.T)                  { testAtol(t) }
 func TestBlocking(t *testing.T)              { testBlocking(t) }
diff --git a/misc/cgo/test/issue31891.c b/misc/cgo/test/issue31891.c
new file mode 100644
index 00000000000..67a0dda2d68
--- /dev/null
+++ b/misc/cgo/test/issue31891.c
@@ -0,0 +1,13 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "_cgo_export.h"
+
+void callIssue31891() {
+    Issue31891A a;
+    useIssue31891A(&a);
+
+    Issue31891B b;
+    useIssue31891B(&b);
+}
diff --git a/misc/cgo/test/testdata/issue9026/issue9026.go b/misc/cgo/test/testdata/issue9026/issue9026.go
index 149c26562ad..0af86e64da4 100644
--- a/misc/cgo/test/testdata/issue9026/issue9026.go
+++ b/misc/cgo/test/testdata/issue9026/issue9026.go
@@ -29,7 +29,7 @@ func Test(t *testing.T) {
 	// Brittle: the assertion may fail spuriously when the algorithm
 	// changes, but should remain stable otherwise.
 	got := fmt.Sprintf("%T %T", in, opts)
-	want := "issue9026._Ctype_struct___0 *issue9026._Ctype_struct___0"
+	want := "issue9026._Ctype_struct___0 *issue9026._Ctype_struct___1"
 	if got != want {
 		t.Errorf("Non-deterministic type names: got %s, want %s", got, want)
 	}
diff --git a/misc/cgo/test/testx.go b/misc/cgo/test/testx.go
index 67def903aba..bb1b50802b6 100644
--- a/misc/cgo/test/testx.go
+++ b/misc/cgo/test/testx.go
@@ -108,6 +108,17 @@ void callMulti(void);
 // issue 28772 part 2 - part 1 in issuex.go
 #define issue28772Constant2 2
 
+
+// issue 31891
+typedef struct {
+	long obj;
+} Issue31891A;
+
+typedef struct {
+	long obj;
+} Issue31891B;
+
+void callIssue31891(void);
 */
 import "C"
 
@@ -517,3 +528,15 @@ func test20910(t *testing.T) {
 // issue 28772 part 2
 
 const issue28772Constant2 = C.issue28772Constant2
+
+// issue 31891
+
+//export useIssue31891A
+func useIssue31891A(c *C.Issue31891A) {}
+
+//export useIssue31891B
+func useIssue31891B(c *C.Issue31891B) {}
+
+func test31891(t *testing.T) {
+	C.callIssue31891()
+}
diff --git a/src/cmd/cgo/gcc.go b/src/cmd/cgo/gcc.go
index 12d47496773..fcab494ea0d 100644
--- a/src/cmd/cgo/gcc.go
+++ b/src/cmd/cgo/gcc.go
@@ -2189,6 +2189,11 @@ func (c *typeConv) FinishType(pos token.Pos) {
 // Type returns a *Type with the same memory layout as
 // dtype when used as the type of a variable or a struct field.
 func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
+	return c.loadType(dtype, pos, "")
+}
+
+// loadType recursively loads the requested dtype and its dependency graph.
+func (c *typeConv) loadType(dtype dwarf.Type, pos token.Pos, parent string) *Type {
 	// Always recompute bad pointer typedefs, as the set of such
 	// typedefs changes as we see more types.
 	checkCache := true
@@ -2196,7 +2201,9 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 		checkCache = false
 	}
 
-	key := dtype.String()
+	// The cache key should be relative to its parent.
+	// See issue https://golang.org/issue/31891
+	key := parent + " > " + dtype.String()
 
 	if checkCache {
 		if t, ok := c.m[key]; ok {
@@ -2236,7 +2243,7 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 			// Translate to zero-length array instead.
 			count = 0
 		}
-		sub := c.Type(dt.Type, pos)
+		sub := c.loadType(dt.Type, pos, key)
 		t.Align = sub.Align
 		t.Go = &ast.ArrayType{
 			Len: c.intExpr(count),
@@ -2381,7 +2388,7 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 		c.ptrs[key] = append(c.ptrs[key], t)
 
 	case *dwarf.QualType:
-		t1 := c.Type(dt.Type, pos)
+		t1 := c.loadType(dt.Type, pos, key)
 		t.Size = t1.Size
 		t.Align = t1.Align
 		t.Go = t1.Go
@@ -2465,7 +2472,7 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 		}
 		name := c.Ident("_Ctype_" + dt.Name)
 		goIdent[name.Name] = name
-		sub := c.Type(dt.Type, pos)
+		sub := c.loadType(dt.Type, pos, key)
 		if c.badPointerTypedef(dt) {
 			// Treat this typedef as a uintptr.
 			s := *sub