diff --git a/parse.y b/parse.y
index bd1717d724..ff00fa8e35 100644
--- a/parse.y
+++ b/parse.y
@@ -8659,7 +8659,8 @@ parse_percent(struct parser_params *p, const int space_seen, const enum lex_stat
 
 	c = nextc(p);
       quotation:
-	if (c == -1 || !ISALNUM(c)) {
+	if (c == -1) goto unterminated;
+	if (!ISALNUM(c)) {
 	    term = c;
 	    if (!ISASCII(c)) goto unknown;
 	    c = 'Q';
@@ -8677,6 +8678,7 @@ parse_percent(struct parser_params *p, const int space_seen, const enum lex_stat
 	    }
 	}
 	if (term == -1) {
+	  unterminated:
 	    compile_error(p, "unterminated quoted string meets end of file");
 	    return 0;
 	}
diff --git a/test/ruby/test_parse.rb b/test/ruby/test_parse.rb
index 5f638afa01..4b7a12c8ef 100644
--- a/test/ruby/test_parse.rb
+++ b/test/ruby/test_parse.rb
@@ -601,6 +601,7 @@ class TestParse < Test::Unit::TestCase
     assert_syntax_error('%z()', /unknown type/)
     assert_syntax_error("%\u3042", /unknown type/)
     assert_syntax_error("%q\u3042", /unknown type/)
+    assert_syntax_error("%", /unterminated quoted string/)
   end
 
   def test_symbol