diff --git a/src/main/kotlin/fr/postgresjson/connexion/Connection.kt b/src/main/kotlin/fr/postgresjson/connexion/Connection.kt
index 1c33eab..9108304 100644
--- a/src/main/kotlin/fr/postgresjson/connexion/Connection.kt
+++ b/src/main/kotlin/fr/postgresjson/connexion/Connection.kt
@@ -114,7 +114,7 @@ class Requester (
         val functionRegex = """create .*(procedure|function) *(?<name>[^(\s]+)\s*\((?<params>(\s*((IN|OUT|INOUT|VARIADIC)?\s+)?([^\s,)]+\s+)?([^\s,)]+)(\s+(?:default\s|=)\s*[^\s,)]+)?\s*(,|(?=\))))*)\) *(?<return>RETURNS *[^ ]+)?"""
             .toRegex(setOf(IGNORE_CASE, MULTILINE))
 
-        val paramsRegex = """\s*(?<param>((?<direction>IN|OUT|INOUT|VARIADIC)?\s+)?(?<name>[^\s,)]+\s+)?(?<type>[^\s,)]+)(\s+(?:default\s|=)\s*[^\s,)]+)?)\s*(,|$)"""
+        val paramsRegex = """\s*(?<param>((?<direction>IN|OUT|INOUT|VARIADIC)?\s+)?(?<name>[^\s,)]+\s+)?(?<type>[^\s,)]+)(\s+(?<default>default\s|=)\s*[^\s,)]+)?)\s*(,|$)"""
             .toRegex(setOf(IGNORE_CASE, MULTILINE))
 
         return functionRegex.findAll(functionContent).map { queryMatch ->
@@ -129,7 +129,8 @@ class Requester (
                     Function.Parameter(
                         paramsMatch.groups["name"]!!.value.trim(),
                         paramsMatch.groups["type"]!!.value.trim(),
-                        paramsMatch.groups["direction"]?.value?.trim())
+                        paramsMatch.groups["direction"]?.value?.trim(),
+                        paramsMatch.groups["default"]?.value?.trim())
                 }.toList()
             } else {
                 listOf()
@@ -173,7 +174,7 @@ class Requester (
 
     class Function(val name: String, val parameters: List<Parameter>, private val connection : Connection) {
 
-        class Parameter(val name: String, val type: String, direction: Direction? = Direction.IN)
+        class Parameter(val name: String, val type: String, direction: Direction? = Direction.IN, val default: Any? = null)
         {
             val direction: Direction
 
@@ -184,10 +185,11 @@ class Requester (
                     this.direction = direction
                 }
             }
-            constructor(name: String, type: String, direction: String? = "IN") : this(
+            constructor(name: String, type: String, direction: String? = "IN", default: Any? = null) : this(
                 name = name,
                 type = type,
-                direction = direction?.let { Direction.valueOf(direction.toUpperCase())}
+                direction = direction?.let { Direction.valueOf(direction.toUpperCase())},
+                default = default
             )
             enum class Direction { IN, OUT, INOUT }
         }
@@ -197,8 +199,8 @@ class Requester (
         }
 
         fun <T, R : EntityI<T?>?> selectOne(typeReference: TypeReference<R>, values: List<String?> = emptyList()): R? {
-            val placeholder = List(values.size) {"?"}.joinToString(separator=", ")
-            val sql = "SELECT * FROM $name (${placeholder})"
+            val args = compileArgs(values)
+            val sql = "SELECT * FROM $name ($args)"
 
             return connection.selectOne(sql, typeReference, values)
         }
@@ -206,13 +208,25 @@ class Requester (
         inline fun <T, reified R: EntityI<T?>?> selectOne(values: List<String?> = emptyList()): R? = selectOne(object: TypeReference<R>() {}, values)
 
         fun <T, R : List<EntityI<T?>?>> select(typeReference: TypeReference<R>, values: List<Any?> = emptyList()): R? {
-            val placeholder = List(values.size) {"?"}.joinToString(separator=", ")
-            val sql = "SELECT * FROM $name ($placeholder)"
+            val args = compileArgs(values)
+            val sql = "SELECT * FROM $name ($args)"
 
             return connection.select(sql, typeReference, values)
         }
 
         inline fun <T, reified R: List<EntityI<T?>?>> select(values: List<Any?> = emptyList()): R? = select(object: TypeReference<R>() {}, values)
+
+        private fun compileArgs(values: List<Any?>): String {
+            val placeholders = values
+                .filterIndexed { index, any ->
+                    this.parameters[index].default === null || any !== null
+                }
+                .mapIndexed { index, any ->
+                    "?::" + this.parameters[index].type
+                }
+
+            return placeholders.joinToString(separator=", ")
+        }
     }
 }
 
diff --git a/src/test/kotlin/fr/postgresjson/ConnectionTest.kt b/src/test/kotlin/fr/postgresjson/ConnectionTest.kt
index 7f1f19f..be06db6 100644
--- a/src/test/kotlin/fr/postgresjson/ConnectionTest.kt
+++ b/src/test/kotlin/fr/postgresjson/ConnectionTest.kt
@@ -2,7 +2,7 @@ package fr.postgresjson
 
 import fr.postgresjson.connexion.Connection
 import fr.postgresjson.entity.IdEntity
-import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Assertions.*
 import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.TestInstance
@@ -46,4 +46,11 @@ class ConnectionTest(): TestAbstract() {
         assertTrue(objs[0].id == 1)
         assertTrue(objs[0].test!!.id == 1)
     }
+
+    @Test
+    fun callRequestWithArgs() {
+        val result: ObjTest? = connection.selectOne("select json_build_object('id', 1, 'name', ?::text)", listOf("myName"))
+        assertNotNull(result)
+        assertEquals("myName", result!!.name)
+    }
 }
\ No newline at end of file
diff --git a/src/test/kotlin/fr/postgresjson/RequestTest.kt b/src/test/kotlin/fr/postgresjson/RequestTest.kt
index efc3e8e..79aa602 100644
--- a/src/test/kotlin/fr/postgresjson/RequestTest.kt
+++ b/src/test/kotlin/fr/postgresjson/RequestTest.kt
@@ -26,7 +26,7 @@ class RequestTest: TestAbstract() {
         val objTest: ObjTest? = Requester(getConnextion())
             .addFunction(resources)
             .getFunction("test_function")
-            .selectOne(listOf("ploop", "plip"))
+            .selectOne(listOf("test", "plip"))
         assertEquals(objTest!!.id, 3)
         assertEquals(objTest.name, "test")
     }
diff --git a/src/test/resources/sql/function/Test/function_test.sql b/src/test/resources/sql/function/Test/function_test.sql
index 8e81032..3e3698d 100644
--- a/src/test/resources/sql/function/Test/function_test.sql
+++ b/src/test/resources/sql/function/Test/function_test.sql
@@ -3,6 +3,6 @@ LANGUAGE plpgsql
 AS
 $$
 BEGIN
-    result = json_build_object('id', 3, 'name', 'test');
+    result = json_build_object('id', 3, 'name', name);
 END;
 $$
\ No newline at end of file