diff --git a/compiler/ssa/abi/abi.go b/compiler/ssa/abi/abi.go
index 0039f636..193034a0 100644
--- a/compiler/ssa/abi/abi.go
+++ b/compiler/ssa/abi/abi.go
@@ -190,6 +190,8 @@ func (b *Builder) TypeName(t types.Type) (ret string, pub bool) {
 			s = "<-chan"
 		}
 		return fmt.Sprintf("%s %s", s, elem), pub
+	case *types.Alias:
+		return b.TypeName(types.Unalias(t))
 	}
 	log.Panicf("todo: %T\n", t)
 	return
diff --git a/compiler/ssa/abitype.go b/compiler/ssa/abitype.go
index aa985ccc..9f184132 100644
--- a/compiler/ssa/abitype.go
+++ b/compiler/ssa/abitype.go
@@ -77,6 +77,8 @@ func (b Builder) abiTypeOf(t types.Type) func() Expr {
 		return b.abiChanOf(t)
 	case *types.Map:
 		return b.abiMapOf(t)
+	case *types.Alias:
+		return b.abiTypeOf(types.Unalias(t))
 	}
 	panic("todo")
 }