diff --git a/liberty/LibertyLex.ll b/liberty/LibertyLex.ll
index 617d004a..4001db06 100644
--- a/liberty/LibertyLex.ll
+++ b/liberty/LibertyLex.ll
@@ -70,7 +70,7 @@ HNAME ({PIN_NAME}|{BUS_NAME}|{MIXED_NAME})([\/.]({PIN_NAME}|{BUS_NAME}|{MIXED_NA
 /* default_operating_conditions : slow_100_3.00 ; */
 /* revision : 1.0.17; */
 /* default_wire_load : xc2v250-5_avg; */
-TOKEN ({ALPHA}|{DIGIT}|_)({ALPHA}|{DIGIT}|[._\-:])*
+TOKEN ({ALPHA}|{DIGIT}|_)({ALPHA}|{DIGIT}|[._\-])*
 /* bus_naming_style : %s[%d] ; */
 BUS_STYLE "%s"{BUS_LEFT}"%d"{BUS_RIGHT}
 PUNCTUATION [,\:;|(){}+*&!'=]
diff --git a/liberty/LibertyParse.yy b/liberty/LibertyParse.yy
index 1424fa29..609826f7 100644
--- a/liberty/LibertyParse.yy
+++ b/liberty/LibertyParse.yy
@@ -86,6 +86,18 @@ group:
 	{ sta::libertyGroupBegin($1, $3, $5); }
 	statements '}' semi_opt
 	{ $$ = sta::libertyGroupEnd(); }
+        /* group(name1:name2) { stmts } */
+|	KEYWORD '(' KEYWORD ':' KEYWORD ')' line '{'
+	{ sta::LibertyAttrValueSeq *args = sta::makeLibertyGroupColonArgs($3, $5);
+          sta::libertyGroupBegin($1, args, $7); }
+	statements '}' semi_opt
+	{ $$ = sta::libertyGroupEnd(); }
+        /* group(name1:name2); */
+|	KEYWORD '(' KEYWORD ':' KEYWORD ')' line 
+	{ sta::LibertyAttrValueSeq *args = sta::makeLibertyGroupColonArgs($3, $5);
+          sta::libertyGroupBegin($1, args, $7); }
+	semi_opt
+	{ $$ = sta::libertyGroupEnd(); }
 	;
 
 line: /* empty */
diff --git a/liberty/LibertyParser.cc b/liberty/LibertyParser.cc
index 45a79802..f172229a 100644
--- a/liberty/LibertyParser.cc
+++ b/liberty/LibertyParser.cc
@@ -127,6 +127,21 @@ libertyGroupEnd()
   }
 }
 
+// Helper for brain damaged group args with embedded colon.
+// group(name1:name2) { stmts }
+LibertyAttrValueSeq *
+makeLibertyGroupColonArgs(const char *name1,
+                          const char *name2)
+{
+  LibertyAttrValueSeq *attr_values = new sta::LibertyAttrValueSeq;
+  char *str_arg = stringPrint("%s:%s", name1, name2);
+  stringDelete(name1);
+  stringDelete(name2);
+  LibertyAttrValue *arg = makeLibertyStringAttrValue(str_arg);
+  attr_values->push_back(arg);
+  return attr_values;
+}
+
 ////////////////////////////////////////////////////////////////
 
 LibertyStmt::LibertyStmt(int line) :
diff --git a/liberty/LibertyParser.hh b/liberty/LibertyParser.hh
index bd3a8804..8b82059c 100644
--- a/liberty/LibertyParser.hh
+++ b/liberty/LibertyParser.hh
@@ -303,6 +303,9 @@ void
 libertyGroupBegin(const char *type,
 		  LibertyAttrValueSeq *params,
 		  int line);
+LibertyAttrValueSeq *
+makeLibertyGroupColonArgs(const char *name1,
+                          const char *name2);
 LibertyGroup *
 libertyGroupEnd();
 LibertyGroup *