diff --git a/internal/jet/expression.go b/internal/jet/expression.go
index d62920c..05b1797 100644
--- a/internal/jet/expression.go
+++ b/internal/jet/expression.go
@@ -278,7 +278,7 @@ type customExpression struct {
 	parts []Serializer
 }
 
-func newCustomExpression(parts ...Serializer) Expression {
+func CustomExpression(parts ...Serializer) Expression {
 	ret := customExpression{
 		parts: parts,
 	}
diff --git a/internal/jet/func_expression.go b/internal/jet/func_expression.go
index 6036b8d..7e49880 100644
--- a/internal/jet/func_expression.go
+++ b/internal/jet/func_expression.go
@@ -548,7 +548,7 @@ func TO_TIMESTAMP(timestampzStr, format StringExpression) TimestampzExpression {
 
 // EXTRACT extracts time component from time expression
 func EXTRACT(field string, from Expression) Expression {
-	return newCustomExpression(Token("EXTRACT("), Token(field), Token("FROM"), from, Token(")"))
+	return CustomExpression(Token("EXTRACT("), Token(field), Token("FROM"), from, Token(")"))
 }
 
 // CURRENT_DATE returns current date
diff --git a/internal/jet/group_by_clause.go b/internal/jet/group_by_clause.go
index 5f0c4b1..017bb4e 100644
--- a/internal/jet/group_by_clause.go
+++ b/internal/jet/group_by_clause.go
@@ -35,7 +35,7 @@ func GROUPING(expressions ...Expression) IntegerExpression {
 // WITH_ROLLUP operator is used with the GROUP BY clause to generate all prefixes of a group of columns including the empty list.
 // It creates extra rows in the result set that represent the subtotal values for each combination of columns.
 func WITH_ROLLUP(expressions ...Expression) GroupByClause {
-	return newCustomExpression(
+	return CustomExpression(
 		parametersSerializer(expressions), Token("WITH ROLLUP"),
 	)
 }
diff --git a/mysql/expressions.go b/mysql/expressions.go
index b3f4ce5..53b1fa7 100644
--- a/mysql/expressions.go
+++ b/mysql/expressions.go
@@ -70,6 +70,12 @@ var DateTimeExp = jet.TimestampExp
 // Does not add sql cast to generated sql builder output.
 var TimestampExp = jet.TimestampExp
 
+// CustomExpression is used to define custom expressions.
+var CustomExpression = jet.CustomExpression
+
+// Token is used to define custom token in a custom expression.
+type Token = jet.Token
+
 // RawArgs is type used to pass optional arguments to Raw method
 type RawArgs = map[string]interface{}
 
diff --git a/postgres/expressions.go b/postgres/expressions.go
index 759f055..9872910 100644
--- a/postgres/expressions.go
+++ b/postgres/expressions.go
@@ -111,6 +111,12 @@ var (
 	TstzRangeExp = jet.TstzRangeExp
 )
 
+// CustomExpression is used to define custom expressions.
+var CustomExpression = jet.CustomExpression
+
+// Token is used to define custom token in a custom expression.
+type Token = jet.Token
+
 // RawArgs is type used to pass optional arguments to Raw method
 type RawArgs = map[string]interface{}
 
diff --git a/sqlite/expressions.go b/sqlite/expressions.go
index 93bb7b7..42ccc96 100644
--- a/sqlite/expressions.go
+++ b/sqlite/expressions.go
@@ -73,6 +73,12 @@ var DateTimeExp = jet.TimestampExp
 // Does not add sql cast to generated sql builder output.
 var TimestampExp = jet.TimestampExp
 
+// CustomExpression is used to define custom expressions.
+var CustomExpression = jet.CustomExpression
+
+// Token is used to define custom token in a custom expression.
+type Token = jet.Token
+
 // RawArgs is type used to pass optional arguments to Raw method
 type RawArgs = map[string]interface{}