diff --git a/backend/js/src/main/scala/aqua/backend/js/JavaScriptCommon.scala b/backend/js/src/main/scala/aqua/backend/js/JavaScriptCommon.scala
index 7eebecd1..02d6588a 100644
--- a/backend/js/src/main/scala/aqua/backend/js/JavaScriptCommon.scala
+++ b/backend/js/src/main/scala/aqua/backend/js/JavaScriptCommon.scala
@@ -18,16 +18,28 @@ object JavaScriptCommon {
   def callBackExprBody(at: ArrowType, callbackName: String): String = {
     val arrowArgumentsToCallbackArgumentsList =
       at.domain.toList.zipWithIndex
-        .map(_._2)
-        .map(idx => s"req.args[$idx]")
+        .map((`type`, idx) => {
+          val valueFromArg = s"req.args[$idx]"
+          `type` match {
+            case OptionType(t) =>
+              s"${valueFromArg}.length === 0 ? null : ${valueFromArg}[0]"
+            case _ => valueFromArg
+          }
+        })
         .concat(List("callParams"))
         .mkString(", ")
 
     val callCallbackStatement = s"$callbackName(${arrowArgumentsToCallbackArgumentsList})"
 
     val callCallbackStatementAndReturn =
-      at.res.fold(s"${callCallbackStatement}; resp.result = {}")(_ =>
-        s"resp.result = ${callCallbackStatement}"
+      at.res.fold(s"${callCallbackStatement}; resp.result = {}")(`type` =>
+        `type` match {
+          case OptionType(t) => s"""
+                                   | var respResult = ${callCallbackStatement};
+                                   | resp.result = respResult === null ? [] : [respResult]
+                                   |""".stripMargin
+          case _ => s"resp.result = ${callCallbackStatement}"
+        }
       )
 
     val tetraplets = FuncRes
diff --git a/backend/ts/src/main/scala/aqua/backend/ts/TypeScriptCommon.scala b/backend/ts/src/main/scala/aqua/backend/ts/TypeScriptCommon.scala
index e95a19c2..084d56fa 100644
--- a/backend/ts/src/main/scala/aqua/backend/ts/TypeScriptCommon.scala
+++ b/backend/ts/src/main/scala/aqua/backend/ts/TypeScriptCommon.scala
@@ -70,16 +70,27 @@ object TypeScriptCommon {
     val arrowArgumentsToCallbackArgumentsList =
       at.domain.toList
         .zipWithIndex
-        .map(_._2)
-        .map(idx => s"req.args[$idx]")
+        .map((`type`, idx) => {
+          val valueFromArg = s"req.args[$idx]"
+          `type` match {
+            case OptionType(t) => s"${valueFromArg}.length === 0 ? null : ${valueFromArg}[0]"
+            case _ => valueFromArg
+          }
+        })
         .concat(List("callParams"))
         .mkString(", ")
 
     val callCallbackStatement = s"$callbackName(${arrowArgumentsToCallbackArgumentsList})"
     
     val callCallbackStatementAndReturn =
-      at.res.fold(s"${callCallbackStatement}; resp.result = {}")(_ =>
-        s"resp.result = ${callCallbackStatement}"
+      at.res.fold(s"${callCallbackStatement}; resp.result = {}")(`type` =>
+        `type` match {
+          case OptionType(t) => s"""
+                                   | var respResult = ${callCallbackStatement};
+                                   | resp.result = respResult === null ? [] : [respResult]
+                                   |""".stripMargin
+          case _ => s"resp.result = ${callCallbackStatement}"
+        }
       )
 
     val tetraplets = FuncRes