diff --git a/skillls/main.py b/skillls/main.py
index 1f60d30..f7c606c 100644
--- a/skillls/main.py
+++ b/skillls/main.py
@@ -90,7 +90,7 @@ class SkillLanguageServer(LanguageServer):
             for col, char in enumerate(line):
                 if col > 0:
                     if fullmatch("\\w", line[col - 1]) and char == "(":
-                        if m := re.match(r"\W+(\w+)$", line[:col]):
+                        if m := re.match(r"\W+([a-zA-Z_][a-zA-Z_0-9]*)$", line[:col]):
                             tok = m.group(1)
                         else:
                             tok = line[col - 1]