diff --git a/docs/usage/expressions.md b/docs/usage/expressions.md
index a0f126b..a37e908 100644
--- a/docs/usage/expressions.md
+++ b/docs/usage/expressions.md
@@ -335,11 +335,11 @@ The following error strings may be returned while compiling or evaluating your e
 
 ```go
 const (
-	ErrorBucket     = "<BUCKET-ERROR>" // Unable to bucket from given value (wrong type)
-	ErrorBucketSize = "<BUCKET-SIZE>"  // Unable to get the size of the bucket (wrong type)
-	ErrorType       = "<BAD-TYPE>"     // Error parsing the principle value of the input because of unexpected type
-	ErrorParsing    = "<PARSE-ERROR>"  // Error parsing the principle value of the input
-	ErrorArgCount   = "<ARGN>"         // Function to not support a variation with the given argument count
-	ErrorArgName    = "<NAME>"         // A variable accessed by a given name does not exist
+	ErrorType     = "<BAD-TYPE>"    // Error parsing the principle value of the input because of unexpected type
+	ErrorParsing  = "<PARSE-ERROR>" // Error parsing the principle value of the input (non-numeric)
+	ErrorArgCount = "<ARGN>"        // Function to not support a variation with the given argument count
+	ErrorConst    = "<CONST>"       // Expected constant value
+	ErrorEnum     = "<ENUM>"        // A given value is not contained within a set
+	ErrorArgName  = "<NAME>"        // A variable accessed by a given name does not exist
 )
 ```
diff --git a/pkg/expressions/stdlib/errors.go b/pkg/expressions/stdlib/errors.go
index 88779b3..05596a0 100644
--- a/pkg/expressions/stdlib/errors.go
+++ b/pkg/expressions/stdlib/errors.go
@@ -1,10 +1,10 @@
 package stdlib
 
 const (
-	ErrorBucket     = "<BUCKET-ERROR>" // Unable to bucket from given value (wrong type)
-	ErrorBucketSize = "<BUCKET-SIZE>"  // Unable to get the size of the bucket (wrong type)
-	ErrorType       = "<BAD-TYPE>"     // Error parsing the principle value of the input because of unexpected type
-	ErrorParsing    = "<PARSE-ERROR>"  // Error parsing the principle value of the input
-	ErrorArgCount   = "<ARGN>"         // Function to not support a variation with the given argument count
-	ErrorArgName    = "<NAME>"         // A variable accessed by a given name does not exist
+	ErrorType     = "<BAD-TYPE>"    // Error parsing the principle value of the input because of unexpected type
+	ErrorParsing  = "<PARSE-ERROR>" // Error parsing the principle value of the input (non-numeric)
+	ErrorArgCount = "<ARGN>"        // Function to not support a variation with the given argument count
+	ErrorConst    = "<CONST>"       // Expected constant value
+	ErrorEnum     = "<ENUM>"        // A given value is not contained within a set
+	ErrorArgName  = "<NAME>"        // A variable accessed by a given name does not exist
 )
diff --git a/pkg/expressions/stdlib/funcsCommon.go b/pkg/expressions/stdlib/funcsCommon.go
index fcec556..5082a6a 100644
--- a/pkg/expressions/stdlib/funcsCommon.go
+++ b/pkg/expressions/stdlib/funcsCommon.go
@@ -26,12 +26,12 @@ func kfBucket(args []KeyBuilderStage) KeyBuilderStage {
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
 		val, err := strconv.Atoi(args[0](context))
 		if err != nil {
-			return ErrorBucket
+			return ErrorType
 		}
 
 		bucketSize, err := strconv.Atoi(args[1](context))
 		if err != nil {
-			return ErrorBucketSize
+			return ErrorType
 		}
 
 		return strconv.Itoa((val / bucketSize) * bucketSize)
diff --git a/pkg/expressions/stdlib/funcsTime.go b/pkg/expressions/stdlib/funcsTime.go
index fb00953..1f63729 100644
--- a/pkg/expressions/stdlib/funcsTime.go
+++ b/pkg/expressions/stdlib/funcsTime.go
@@ -214,7 +214,7 @@ func timeBucketToFormat(name string) string {
 	} else if isPartialString(name, "years") {
 		return "2006"
 	}
-	return ErrorBucket
+	return ErrorEnum
 }
 
 // {func <time> <bucket> [format:auto] [tz:utc]}
@@ -269,7 +269,7 @@ func kfTimeAttr(args []KeyBuilderStage) KeyBuilderStage {
 
 	attrFunc, hasAttrFunc := attrType[strings.ToUpper(attrName)]
 	if !hasAttrFunc {
-		return stageError(ErrorBucket)
+		return stageError(ErrorEnum)
 	}
 
 	return KeyBuilderStage(func(context KeyBuilderContext) string {
diff --git a/pkg/expressions/stdlib/funcs_test.go b/pkg/expressions/stdlib/funcs_test.go
index c993ca0..8f70278 100644
--- a/pkg/expressions/stdlib/funcs_test.go
+++ b/pkg/expressions/stdlib/funcs_test.go
@@ -59,7 +59,7 @@ func TestBucket(t *testing.T) {
 		mockContext("1000", "1200", "1234"),
 		"{bucket {0} 1000} {bucket {1} 1000} {bucket {2} 1000} {bucket {2} 100}",
 		"1000 1000 1000 1200")
-	testExpression(t, mockContext(), "{bucket abc 100} {bucket 1}", "<BUCKET-ERROR> <ARGN>")
+	testExpression(t, mockContext(), "{bucket abc 100} {bucket 1}", "<BAD-TYPE> <ARGN>")
 }
 
 func TestExpBucket(t *testing.T) {