diff --git a/pkg/expressions/stdlib/funcsComparators.go b/pkg/expressions/stdlib/funcsComparators.go
index 6652644..687b2a3 100644
--- a/pkg/expressions/stdlib/funcsComparators.go
+++ b/pkg/expressions/stdlib/funcsComparators.go
@@ -10,7 +10,7 @@ import (
 func stringComparator(equation func(string, string) string) KeyBuilderFunction {
 	return KeyBuilderFunction(func(args []KeyBuilderStage) KeyBuilderStage {
 		if len(args) < 2 {
-			return stageError(ErrorArgCount)
+			return stageLiteral(ErrorArgCount)
 		}
 		return KeyBuilderStage(func(context KeyBuilderContext) string {
 			val := args[0](context)
@@ -27,7 +27,7 @@ func stringComparator(equation func(string, string) string) KeyBuilderFunction {
 func arithmaticEqualityHelper(test func(float64, float64) bool) KeyBuilderFunction {
 	return KeyBuilderFunction(func(args []KeyBuilderStage) KeyBuilderStage {
 		if len(args) != 2 {
-			return stageError(ErrorArgCount)
+			return stageLiteral(ErrorArgCount)
 		}
 		return KeyBuilderStage(func(context KeyBuilderContext) string {
 			left, err := strconv.ParseFloat(args[0](context), 64)
@@ -49,7 +49,7 @@ func arithmaticEqualityHelper(test func(float64, float64) bool) KeyBuilderFuncti
 
 func kfNot(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) != 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		if Truthy(args[0](context)) {
@@ -86,7 +86,7 @@ func kfOr(args []KeyBuilderStage) KeyBuilderStage {
 // {like string contains}
 func kfLike(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) != 2 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		val := args[0](context)
@@ -102,7 +102,7 @@ func kfLike(args []KeyBuilderStage) KeyBuilderStage {
 // {if truthy val elseVal}
 func kfIf(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) < 2 || len(args) > 3 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		ifVal := args[0](context)
diff --git a/pkg/expressions/stdlib/funcsStrings.go b/pkg/expressions/stdlib/funcsStrings.go
index f2c20c3..dc78de0 100644
--- a/pkg/expressions/stdlib/funcsStrings.go
+++ b/pkg/expressions/stdlib/funcsStrings.go
@@ -12,7 +12,7 @@ import (
 // {prefix string prefix}
 func kfPrefix(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) != 2 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		val := args[0](context)
@@ -28,7 +28,7 @@ func kfPrefix(args []KeyBuilderStage) KeyBuilderStage {
 // {suffix string suffix}
 func kfSuffix(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) != 2 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		val := args[0](context)
@@ -149,7 +149,7 @@ func selectField(s string, idx int) string {
 // just like fmt.Sprintf
 func kfFormat(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) < 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		format := args[0](context)
@@ -165,7 +165,7 @@ func kfFormat(args []KeyBuilderStage) KeyBuilderStage {
 
 func kfHumanizeInt(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) != 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		val, err := strconv.Atoi(args[0](context))
@@ -178,7 +178,7 @@ func kfHumanizeInt(args []KeyBuilderStage) KeyBuilderStage {
 
 func kfHumanizeFloat(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) != 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		val, err := strconv.ParseFloat(args[0](context), 64)
@@ -191,12 +191,12 @@ func kfHumanizeFloat(args []KeyBuilderStage) KeyBuilderStage {
 
 func kfBytesize(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) < 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 
 	precision, err := strconv.Atoi(EvalStageIndexOrDefault(args, 1, "0"))
 	if err != nil {
-		return stageError(ErrorType)
+		return stageLiteral(ErrorType)
 	}
 
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
diff --git a/pkg/expressions/stdlib/funcsTime.go b/pkg/expressions/stdlib/funcsTime.go
index a56c155..1115bb4 100644
--- a/pkg/expressions/stdlib/funcsTime.go
+++ b/pkg/expressions/stdlib/funcsTime.go
@@ -111,7 +111,7 @@ func smartDateParseWrapper(format string, tz *time.Location, dateStage KeyBuilde
 // {func <time> [format:cache] [tz:utc]}
 func kfTimeParse(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) < 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 
 	// Special key-words for time (eg "now")
@@ -129,7 +129,7 @@ func kfTimeParse(args []KeyBuilderStage) KeyBuilderStage {
 	format := EvalStageIndexOrDefault(args, 1, "")
 	tz, tzOk := parseTimezoneLocation(EvalStageIndexOrDefault(args, 2, ""))
 	if !tzOk {
-		return stageError(ErrorParsing)
+		return stageLiteral(ErrorParsing)
 	}
 
 	return smartDateParseWrapper(format, tz, args[0], func(t time.Time) string {
@@ -140,13 +140,13 @@ func kfTimeParse(args []KeyBuilderStage) KeyBuilderStage {
 // {func <unixtime> [format:RFC3339] [tz:utc]}
 func kfTimeFormat(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) < 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 	format := namedTimeFormatToFormat(EvalStageIndexOrDefault(args, 1, defaultTimeFormat))
 
 	tz, tzOk := parseTimezoneLocation(EvalStageIndexOrDefault(args, 2, ""))
 	if !tzOk {
-		return stageError(ErrorParsing)
+		return stageLiteral(ErrorParsing)
 	}
 
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
@@ -165,7 +165,7 @@ func kfTimeFormat(args []KeyBuilderStage) KeyBuilderStage {
 // {func <duration_string>}
 func kfDuration(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) != 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
@@ -183,7 +183,7 @@ func kfDuration(args []KeyBuilderStage) KeyBuilderStage {
 // {func <secs>} format seconds to duration
 func kfDurationFormat(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) != 1 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
@@ -220,14 +220,14 @@ func timeBucketToFormat(name string) string {
 // {func <time> <bucket> [format:auto] [tz:utc]}
 func kfBucketTime(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) < 2 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 
 	bucketFormat := timeBucketToFormat(EvalStageOrDefault(args[1], "day"))
 	parseFormat := EvalStageIndexOrDefault(args, 2, "")
 	tz, tzOk := parseTimezoneLocation(EvalStageIndexOrDefault(args, 3, ""))
 	if !tzOk {
-		return stageError(ErrorParsing)
+		return stageLiteral(ErrorParsing)
 	}
 
 	return smartDateParseWrapper(parseFormat, tz, args[0], func(t time.Time) string {
@@ -255,21 +255,21 @@ var attrType = map[string](func(t time.Time) string){
 // {func <time> <attr> [tz:utc]}
 func kfTimeAttr(args []KeyBuilderStage) KeyBuilderStage {
 	if len(args) < 2 || len(args) > 3 {
-		return stageError(ErrorArgCount)
+		return stageLiteral(ErrorArgCount)
 	}
 
 	attrName, hasAttrName := EvalStaticStage(args[1])
 	if !hasAttrName {
-		return stageError(ErrorType)
+		return stageLiteral(ErrorType)
 	}
 	tz, tzOk := parseTimezoneLocation(EvalStageIndexOrDefault(args, 2, ""))
 	if !tzOk {
-		return stageError(ErrorParsing)
+		return stageLiteral(ErrorParsing)
 	}
 
 	attrFunc, hasAttrFunc := attrType[strings.ToUpper(attrName)]
 	if !hasAttrFunc {
-		return stageError(ErrorEnum)
+		return stageLiteral(ErrorEnum)
 	}
 
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
diff --git a/pkg/expressions/stdlib/funcsTime_test.go b/pkg/expressions/stdlib/funcsTime_test.go
index 3ba5eaf..7c98c94 100644
--- a/pkg/expressions/stdlib/funcsTime_test.go
+++ b/pkg/expressions/stdlib/funcsTime_test.go
@@ -95,7 +95,7 @@ func TestDurationFormat(t *testing.T) {
 	testExpression(t,
 		mockContext("14400"),
 		"{durationformat {0} b}",
-		"<<ARGN>>")
+		"<ARGN>")
 }
 
 // Bucketing
@@ -153,21 +153,21 @@ func TestTimeAttrToBadTZ(t *testing.T) {
 	testExpression(t,
 		mockContext("14/Apr/2016 01:00:00"),
 		"{timeattr {time {0}} weekday asdf}",
-		"<<PARSE-ERROR>>")
+		"<PARSE-ERROR>")
 }
 
 func TestTimeAttrArgError(t *testing.T) {
 	testExpression(t,
 		mockContext("14/Apr/2016 01:00:00"),
 		"{timeattr {time {0}}}",
-		"<<ARGN>>")
+		"<ARGN>")
 }
 
 func TestTimeAttrArgErrorExtra(t *testing.T) {
 	testExpression(t,
 		mockContext("14/Apr/2016 01:00:00"),
 		"{timeattr {time {0}} a b c}",
-		"<<ARGN>>")
+		"<ARGN>")
 }
 
 // Utilities
diff --git a/pkg/expressions/stdlib/stages.go b/pkg/expressions/stdlib/stages.go
index 5dc74e9..888e571 100644
--- a/pkg/expressions/stdlib/stages.go
+++ b/pkg/expressions/stdlib/stages.go
@@ -1,8 +1,6 @@
 package stdlib
 
 import (
-	"fmt"
-
 	. "rare/pkg/expressions" //lint:ignore ST1001 Legacy
 )
 
@@ -11,10 +9,3 @@ func stageLiteral(s string) KeyBuilderStage {
 		return s
 	})
 }
-
-func stageError(msg string) KeyBuilderStage {
-	errMessage := fmt.Sprintf("<%s>", msg)
-	return KeyBuilderStage(func(context KeyBuilderContext) string {
-		return errMessage
-	})
-}