diff --git a/hibernate-core/src/main/java/org/hibernate/dialect/function/array/ArrayToStringFunction.java b/hibernate-core/src/main/java/org/hibernate/dialect/function/array/ArrayToStringFunction.java
index ff4ef67d8597..654fb80ec92c 100644
--- a/hibernate-core/src/main/java/org/hibernate/dialect/function/array/ArrayToStringFunction.java
+++ b/hibernate-core/src/main/java/org/hibernate/dialect/function/array/ArrayToStringFunction.java
@@ -32,8 +32,7 @@ public ArrayToStringFunction(TypeConfiguration typeConfiguration) {
 				"array_to_string",
 				FunctionKind.NORMAL,
 				StandardArgumentsValidators.composite(
-					new ArgumentTypesValidator( StandardArgumentsValidators.between( 2, 3 ), ANY, STRING, ANY ),
-					new ArrayAndElementArgumentValidator( 0, 2 )
+					new ArgumentTypesValidator( StandardArgumentsValidators.between( 2, 3 ), ANY, STRING, ANY )
 				),
 				StandardFunctionReturnTypeResolvers.invariant(
 						typeConfiguration.getBasicTypeRegistry().resolve( StandardBasicTypes.STRING )
diff --git a/hibernate-core/src/main/java/org/hibernate/dialect/function/array/H2ArrayToStringFunction.java b/hibernate-core/src/main/java/org/hibernate/dialect/function/array/H2ArrayToStringFunction.java
index 3b3d1bec2c67..b097265ade6d 100644
--- a/hibernate-core/src/main/java/org/hibernate/dialect/function/array/H2ArrayToStringFunction.java
+++ b/hibernate-core/src/main/java/org/hibernate/dialect/function/array/H2ArrayToStringFunction.java
@@ -40,13 +40,13 @@ public void render(
 		arrayExpression.accept( walker );
 		sqlAppender.append( " is not null then coalesce((select listagg(" );
 		if ( defaultExpression != null ) {
-			sqlAppender.append( "coalesce(" );
+			sqlAppender.append( "coalesce(cast(" );
 		}
 		sqlAppender.append( "array_get(" );
 		arrayExpression.accept( walker );
 		sqlAppender.append(",i.idx)" );
 		if ( defaultExpression != null ) {
-			sqlAppender.append( "," );
+			sqlAppender.append( " as varchar2)," );
 			defaultExpression.accept( walker );
 			sqlAppender.append( ")" );
 		}
diff --git a/hibernate-core/src/main/java/org/hibernate/dialect/function/array/HSQLArrayToStringFunction.java b/hibernate-core/src/main/java/org/hibernate/dialect/function/array/HSQLArrayToStringFunction.java
index ff9ef8e54480..a94c79f85381 100644
--- a/hibernate-core/src/main/java/org/hibernate/dialect/function/array/HSQLArrayToStringFunction.java
+++ b/hibernate-core/src/main/java/org/hibernate/dialect/function/array/HSQLArrayToStringFunction.java
@@ -36,11 +36,11 @@ public void render(
 		arrayExpression.accept( walker );
 		sqlAppender.append( " is not null then coalesce((select group_concat(" );
 		if ( defaultExpression != null ) {
-			sqlAppender.append( "coalesce(" );
+			sqlAppender.append( "coalesce(cast(" );
 		}
 		sqlAppender.append( "t.val" );
 		if ( defaultExpression != null ) {
-			sqlAppender.append( "," );
+			sqlAppender.append( " as varchar)," );
 			defaultExpression.accept( walker );
 			sqlAppender.append( ")" );
 		}
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/type/BooleanArrayToStringTest.java b/hibernate-core/src/test/java/org/hibernate/orm/test/type/BooleanArrayToStringTest.java
index db6ba058e911..42a55d85cef1 100644
--- a/hibernate-core/src/test/java/org/hibernate/orm/test/type/BooleanArrayToStringTest.java
+++ b/hibernate-core/src/test/java/org/hibernate/orm/test/type/BooleanArrayToStringTest.java
@@ -7,6 +7,7 @@
 import jakarta.persistence.Entity;
 import jakarta.persistence.Id;
 import org.hibernate.dialect.OracleDialect;
+import org.hibernate.dialect.PostgreSQLDialect;
 import org.hibernate.testing.orm.junit.DialectFeatureChecks;
 import org.hibernate.testing.orm.junit.DomainModel;
 import org.hibernate.testing.orm.junit.Jira;
@@ -37,9 +38,17 @@ public void testBooleanArrayToStringFunction(SessionFactoryScope scope) {
 		);
 		scope.inTransaction(
 				session -> {
+					String expected = session.getDialect().getClass().isAssignableFrom( PostgreSQLDialect.class ) ?
+							"f;f;null;t" : "false;false;null;true";
+
 					String s = session.createQuery( "select array_to_string(t.theBoolean, ';', 'null') "
 							+ "from TestEntity t", String.class ).getSingleResult();
-					Assertions.assertEquals("false;false;null;true", s);
+					Assertions.assertEquals(expected, s.toLowerCase());
+// todo: review these other cases
+//					String s = session.createQuery( "select array_to_string(t.theBoolean, ';', null) "
+//							+ "from TestEntity t", String.class ).getSingleResult();
+//					String s = session.createQuery( "select array_to_string(t.theBoolean, ';') "
+//							+ "from TestEntity t", String.class ).getSingleResult();
 				}
 		);
 		scope.inTransaction(