diff --git a/liberty/LibertyParse.yy b/liberty/LibertyParse.yy
index 50ac1d88..1424fa29 100644
--- a/liberty/LibertyParse.yy
+++ b/liberty/LibertyParse.yy
@@ -50,7 +50,7 @@ int LibertyLex_lex();
 %token <string> STRING KEYWORD
 
 %type <stmt> statement complex_attr simple_attr variable group file
-%type <attr_values> attr_values colon_expr
+%type <attr_values> attr_values
 %type <attr_value> attr_value
 %type <string> string expr expr_term expr_term1 volt_expr
 %type <line> line
@@ -86,10 +86,6 @@ group:
 	{ sta::libertyGroupBegin($1, $3, $5); }
 	statements '}' semi_opt
 	{ $$ = sta::libertyGroupEnd(); }
-|	KEYWORD '(' colon_expr ')' line '{'
-	{ sta::libertyGroupBegin($1, $3, $5); }
-	statements '}' semi_opt
-	{ $$ = sta::libertyGroupEnd(); }
 	;
 
 line: /* empty */
@@ -119,9 +115,6 @@ complex_attr:
 |	KEYWORD '(' attr_values ')' line semi_opt
 	{ $$ = sta::makeLibertyComplexAttr($1, $3, $5); }
 	;
-|	KEYWORD '(' colon_expr ')' line semi_opt
-	{ $$ = sta::makeLibertyComplexAttr($1, $3, $5); }
-	;
 
 attr_values:
 	attr_value
@@ -157,14 +150,6 @@ attr_value:
 	{ $$ = sta::makeLibertyStringAttrValue($1); }
 |	volt_expr
 	{ $$ = sta::makeLibertyStringAttrValue($1); }
-
-/* Colon expressions are normal exprs with a ':' separator. */
-colon_expr:
-	expr ':' expr
-	{ char *expr_str = sta::stringPrint("%s:%s", $1, $3);
-	  $$ = new sta::LibertyAttrValueSeq;
-	  $$->push_back(sta::makeLibertyStringAttrValue(expr_str));
-	}
 	;
 
 /* Voltage expressions are ignored. */
diff --git a/test/ccs_input_ccb_colon.lib b/test/ccs_input_ccb_colon.lib
deleted file mode 100644
index 65a405a2..00000000
--- a/test/ccs_input_ccb_colon.lib
+++ /dev/null
@@ -1,52 +0,0 @@
-library (ccs_input_ccb_colon) {
-  delay_model : "table_lookup";
-  simulation : false;
-  capacitive_load_unit (1,pF);
-  leakage_power_unit : "1pW";
-  current_unit : "1A";
-  pulling_resistance_unit : "1kohm";
-  time_unit : "1ns";
-  voltage_unit : "1v";
-  library_features : "report_delay_calculation";
-  input_threshold_pct_rise : 50;
-  input_threshold_pct_fall : 50;
-  output_threshold_pct_rise : 50;
-  output_threshold_pct_fall : 50;
-  slew_lower_threshold_pct_rise : 30;
-  slew_lower_threshold_pct_fall : 30;
-  slew_upper_threshold_pct_rise : 70;
-  slew_upper_threshold_pct_fall : 70;
-  slew_derate_from_library : 1.0;
-  nom_process : 1.0;
-  nom_temperature : 85.0;
-  nom_voltage : 0.75;
-
-  cell(ccs_input_ccb_colon) { 
-    sensitization_master : sensitization_3pins ; 
-    area : 0.1 ; 
-    dont_touch : true ; 
-    dont_use : true ; 
-
-    pin(A) { 
-      capacitance : 0.0001 ; 
-      direction : input ; 
-      driver_waveform_rise : "driver_waveform_default_rise" ; 
-      driver_waveform_fall : "driver_waveform_default_fall" ; 
-      fall_capacitance : 0.0001 ; 
-      input_voltage : default ; 
-      max_transition : 0.1 ; 
-      related_ground_pin : VSS ; 
-      related_power_pin : VDD ; 
-      rise_capacitance : 0.0001 ; 
-      active_input_ccb(ccs_input_ccb_colon:ck);
-
-      input_ccb(ccs_input_ccb_colon:a) { 
-        is_needed : true ; 
-        is_inverting : true ; 
-        miller_cap_fall : 0.0001 ; 
-        miller_cap_rise : 1e-05 ; 
-        stage_type : both ; 
-      }
-    }
-  }
-}
diff --git a/test/ccs_input_ccb_colon.ok b/test/ccs_input_ccb_colon.ok
deleted file mode 100644
index 50b944a2..00000000
--- a/test/ccs_input_ccb_colon.ok
+++ /dev/null
@@ -1 +0,0 @@
-ccs_input_ccb_colon.lib read
diff --git a/test/ccs_input_ccb_colon.tcl b/test/ccs_input_ccb_colon.tcl
deleted file mode 100644
index ad2aff89..00000000
--- a/test/ccs_input_ccb_colon.tcl
+++ /dev/null
@@ -1,3 +0,0 @@
-# test ccsn with input_ccb having a colon in group name
-read_liberty ccs_input_ccb_colon.lib
-puts "ccs_input_ccb_colon.lib read"
diff --git a/test/regression_vars.tcl b/test/regression_vars.tcl
index e6c35176..359d6455 100644
--- a/test/regression_vars.tcl
+++ b/test/regression_vars.tcl
@@ -133,7 +133,6 @@ record_sta_tests {
   get_noargs
   get_objrefs
   report_checks_src_attr
-  ccs_input_ccb_colon
 }
 
 define_test_group fast [group_tests all]