diff --git a/src/xspice/cmpp/mod_lex.l b/src/xspice/cmpp/mod_lex.l
index 14b1f9043..7cf0acdb9 100644
--- a/src/xspice/cmpp/mod_lex.l
+++ b/src/xspice/cmpp/mod_lex.l
@@ -90,6 +90,7 @@ Z	[0-9A-Za-z_]
 		        }
 
 \"(\\.|[^"\\])*\"	{return TOK_IDENTIFIER;} /* Literal string. */
+\'(\\.|[^'\\])*\'	{return TOK_IDENTIFIER;}
 
 ARGS			{return TOK_ARGS;}
 INIT			{return TOK_INIT;}