diff --git a/gocore/gocore_test.go b/gocore/gocore_test.go
index ab6d980..320bac9 100644
--- a/gocore/gocore_test.go
+++ b/gocore/gocore_test.go
@@ -163,3 +163,15 @@
 		t.Errorf("forward and reverse edges don't match")
 	}
 }
+
+func TestDynamicType(t *testing.T) {
+	p := loadExample(t)
+	for _, g := range p.Globals() {
+		if g.Name == "runtime.indexError" {
+			d := p.DynamicType(g.Type, g.Addr)
+			if d.Name != "runtime.errorString" {
+				t.Errorf("dynamic type wrong: got %s want runtime.errorString", d.Name)
+			}
+		}
+	}
+}
diff --git a/gocore/type.go b/gocore/type.go
index 17c9c57..08b5cd1 100644
--- a/gocore/type.go
+++ b/gocore/type.go
@@ -87,6 +87,29 @@
 	return nil
 }
 
+// DynamicType returns the concrete type stored in the interface type t at address a.
+// If the interface is nil, returns nil.
+func (p *Process) DynamicType(t *Type, a core.Address) *Type {
+	switch t.Kind {
+	default:
+		panic("asking for the dynamic type of a non-interface")
+	case KindEface:
+		x := p.proc.ReadPtr(a)
+		if x == 0 {
+			return nil
+		}
+		return p.runtimeType2Type(x)
+	case KindIface:
+		x := p.proc.ReadPtr(a)
+		if x == 0 {
+			return nil
+		}
+		// Read type out of itab.
+		x = p.proc.ReadPtr(x.Add(p.proc.PtrSize()))
+		return p.runtimeType2Type(x)
+	}
+}
+
 // Convert the address of a runtime._type to a *Type.
 // Guaranteed to return a non-nil *Type.
 func (p *Process) runtimeType2Type(a core.Address) *Type {
@@ -122,7 +145,7 @@
 		// A reflect-generated type.
 		// TODO: The actual name is in the runtime.reflectOffs map.
 		// Too hard to look things up in maps here, just allocate a placeholder for now.
-		name = fmt.Sprintf("reflect.generated%x", a)
+		name = fmt.Sprintf("reflect.generatedType%x", a)
 	}
 
 	// Read ptr/nonptr bits