src/cmd/compile/internal/syntax/parser.go |  2 +-
 test/fixedbugs/issue20789.go              | 13 +++++++++++++

diff --git a/src/cmd/compile/internal/syntax/parser.go b/src/cmd/compile/internal/syntax/parser.go
index fee52c8c3619dd85f5d17c0756a6791f18c2f7a0..bcf56d5faacd99fae8c4cc9215bdcbfce6308704 100644
--- a/src/cmd/compile/internal/syntax/parser.go
+++ b/src/cmd/compile/internal/syntax/parser.go
@@ -654,7 +654,7 @@ 	cx, ok := x.(*CallExpr)
 	if !ok {
 		p.error(fmt.Sprintf("expression in %s must be function call", s.Tok))
 		// already progressed, no need to advance
-		cx := new(CallExpr)
+		cx = new(CallExpr)
 		cx.pos = x.Pos()
 		cx.Fun = p.bad()
 	}
diff --git a/test/fixedbugs/issue20789.go b/test/fixedbugs/issue20789.go
new file mode 100644
index 0000000000000000000000000000000000000000..abc7725ca011dab69c36b7695052ff23dc5a01d8
--- /dev/null
+++ b/test/fixedbugs/issue20789.go
@@ -0,0 +1,13 @@
+// errorcheck
+
+// Copyright 2017 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.
+
+// Make sure this doesn't crash the compiler.
+// (This test should be part of the internal/syntax
+// package, but we don't have a general test framework
+// there yet, so put it here for now. See also #20800.
+
+package e
+func([<-chan<-[func u){go // ERROR "unexpected u", ERROR "must be function call"
\ No newline at end of file