diff --git a/src/cmd/compile/internal/syntax/scanner.go b/src/cmd/compile/internal/syntax/scanner.go
index 1e0ff2e3cc..dbb2387f8f 100644
--- a/src/cmd/compile/internal/syntax/scanner.go
+++ b/src/cmd/compile/internal/syntax/scanner.go
@@ -242,10 +242,6 @@ redo:
 		s.op, s.prec = Or, precAdd
 		goto assignop
 
-	case '~':
-		s.error("bitwise complement operator is ^")
-		fallthrough
-
 	case '^':
 		s.op, s.prec = Xor, precAdd
 		c = s.getr()
diff --git a/src/cmd/compile/internal/syntax/scanner_test.go b/src/cmd/compile/internal/syntax/scanner_test.go
index 4bfe5871fa..0b7c2cfe43 100644
--- a/src/cmd/compile/internal/syntax/scanner_test.go
+++ b/src/cmd/compile/internal/syntax/scanner_test.go
@@ -343,7 +343,7 @@ func TestScanErrors(t *testing.T) {
 		{"\U0001d7d8" /* 𝟘 */, "identifier cannot begin with digit U+1D7D8 '𝟘'", 0, 0},
 		{"foo\U0001d7d8_½" /* foo𝟘_½ */, "invalid identifier character U+00BD '½'", 0, 8 /* byte offset */},
 
-		{"x + ~y", "bitwise complement operator is ^", 0, 4},
+		{"x + ~y", "invalid character U+007E '~'", 0, 4},
 		{"foo$bar = 0", "invalid character U+0024 '$'", 0, 3},
 		{"const x = 0xyz", "malformed hex constant", 0, 12},
 		{"0123456789", "malformed octal constant", 0, 10},
diff --git a/test/fixedbugs/issue23587.go b/test/fixedbugs/issue23587.go
new file mode 100644
index 0000000000..bd5df27755
--- /dev/null
+++ b/test/fixedbugs/issue23587.go
@@ -0,0 +1,12 @@
+// errorcheck
+
+// Copyright 2018 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.
+
+package p
+
+func f(x int) {
+	_ = ~x    // ERROR "invalid character"
+	_ = x ~ x // ERROR "invalid character" "unexpected x at end of statement"
+}