diff --git a/src/bytecode.ts b/src/bytecode.ts
index ae0f7e9..7fc4602 100644
--- a/src/bytecode.ts
+++ b/src/bytecode.ts
@@ -391,7 +391,7 @@ function toBytecodeFromString(str: string): Bytecode /* throws */ {
     if (!trimmed) continue
 
     // Check for label definition (.label_name:)
-    if (/^\.[a-zA-Z_][a-zA-Z0-9_]*:$/.test(trimmed)) {
+    if (/^\.[a-zA-Z_][a-zA-Z0-9_.]*:$/.test(trimmed)) {
       const labelName = trimmed.slice(1, -1)
       labels.set(labelName, cleanLines.length)
       continue