diff --git a/src/scanner.cc b/src/scanner.cc
index 9f38a52bb..a14bcee79 100644
--- a/src/scanner.cc
+++ b/src/scanner.cc
@@ -844,8 +844,11 @@ struct Scanner {
     }
 
     // Open delimiters for literals
-    if (valid_symbols[IDENTIFIER_HASH_KEY] && iswalpha(lexer->lookahead)) {
-      while (iswalpha(lexer->lookahead)) advance(lexer);
+    if (valid_symbols[IDENTIFIER_HASH_KEY]
+        && (iswalpha(lexer->lookahead) || lexer->lookahead == '_')) {
+      while (iswalnum(lexer->lookahead) || lexer->lookahead == '_') {
+        advance(lexer);
+      }
       lexer->mark_end(lexer);
 
       if (lexer->lookahead == ':') {
diff --git a/test/corpus/expressions.txt b/test/corpus/expressions.txt
index 8c17d47c6..e195ab817 100644
--- a/test/corpus/expressions.txt
+++ b/test/corpus/expressions.txt
@@ -642,6 +642,25 @@ foo(bar(a),)
   (method_call (identifier) (argument_list (identifier) (identifier)))
   (method_call (identifier) (argument_list (method_call (identifier) (argument_list (identifier))))))
 
+==============================================
+keyword arguments, no space, trailing comma
+==============================================
+
+foo(a:b)
+foo(a_:b)
+foo(a2:b)
+foo(a_:b,)
+foo(a2:b,)
+
+---
+
+(program
+  (method_call (identifier) (argument_list (pair (symbol) (identifier))))
+  (method_call (identifier) (argument_list (pair (symbol) (identifier))))
+  (method_call (identifier) (argument_list (pair (symbol) (identifier))))
+  (method_call (identifier) (argument_list (pair (symbol) (identifier))))
+  (method_call (identifier) (argument_list (pair (symbol) (identifier)))))
+
 ===============================
 method call with receiver
 ===============================