diff --git a/utbot-framework-api/src/main/kotlin/org/utbot/framework/plugin/api/util/SpringModelUtils.kt b/utbot-framework-api/src/main/kotlin/org/utbot/framework/plugin/api/util/SpringModelUtils.kt
index 3907ca131e..f7dd1aa204 100644
--- a/utbot-framework-api/src/main/kotlin/org/utbot/framework/plugin/api/util/SpringModelUtils.kt
+++ b/utbot-framework-api/src/main/kotlin/org/utbot/framework/plugin/api/util/SpringModelUtils.kt
@@ -720,34 +720,17 @@ object SpringModelUtils {
         methodId: MethodId,
         arguments: List<UtModel>,
         idGenerator: () -> Int
-    ): List< Pair<UtPrimitiveModel, UtAssembleModel> > {
+    ): List<Pair<UtPrimitiveModel, UtArrayModel>> {
         val requestParams = collectArgumentsWithAnnotationModels(methodId, requestParamClassId, arguments)
 
         return requestParams.map { (name, value) ->
             Pair(UtPrimitiveModel(name),
-                UtAssembleModel(
+                UtArrayModel(
                     id = idGenerator(),
-                    classId = listClassId,
-                    modelName = "queryParams",
-                    instantiationCall = UtExecutableCallModel(
-                        instance = null,
-                        executable = constructorId(java.util.ArrayList::class.id),
-                        params = emptyList()
-                    ),
-                    modificationsChainProvider = {
-                        listOf(
-                            UtExecutableCallModel(
-                                instance = this,
-                                executable = methodId(
-                                    classId = listClassId,
-                                    name = "add",
-                                    returnType = booleanClassId,
-                                    arguments = arrayOf(Object::class.id),
-                                ),
-                                params = listOf(value)
-                            )
-                        )
-                    }
+                    classId = getArrayClassIdByElementClassId(objectClassId),
+                    length = 1,
+                    constModel = UtNullModel(objectClassId),
+                    stores = mutableMapOf(0 to value),
                 )
             )
         }
@@ -801,7 +784,7 @@ object SpringModelUtils {
     private fun createUrlTemplateModel(
         requestPath: String,
         pathVariablesModel: UtAssembleModel,
-        requestParamModel: List<Pair<UtPrimitiveModel, UtAssembleModel>>,
+        requestParamModel: List<Pair<UtPrimitiveModel, UtArrayModel>>,
         idGenerator: () -> Int
     ): UtModel {
         val requestPathModel = UtPrimitiveModel(requestPath)
@@ -851,7 +834,7 @@ object SpringModelUtils {
                         executable = MethodId(
                             classId = uriComponentsBuilderClassId,
                             name = "queryParam",
-                            parameters = listOf(stringClassId, collectionClassId),
+                            parameters = listOf(stringClassId, getArrayClassIdByElementClassId(objectClassId)),
                             returnType = uriComponentsBuilderClassId
                         ),
                         params = listOf(name, value),
diff --git a/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/tree/CgVariableConstructor.kt b/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/tree/CgVariableConstructor.kt
index b5cff0deb9..9569f56152 100644
--- a/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/tree/CgVariableConstructor.kt
+++ b/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/tree/CgVariableConstructor.kt
@@ -49,6 +49,7 @@ import org.utbot.framework.plugin.api.util.booleanClassId
 import org.utbot.framework.plugin.api.util.booleanWrapperClassId
 import org.utbot.framework.plugin.api.util.classClassId
 import org.utbot.framework.plugin.api.util.defaultValueModel
+import org.utbot.framework.plugin.api.util.executable
 import org.utbot.framework.plugin.api.util.jField
 import org.utbot.framework.plugin.api.util.findFieldByIdOrNull
 import org.utbot.framework.plugin.api.util.id
@@ -188,7 +189,7 @@ open class CgVariableConstructor(val context: CgContext) :
         }
 
         for ((fieldId, fieldModel) in model.fields) {
-            val variableForField = getOrCreateVariable(fieldModel)
+            val variableForField = getOrCreateVariable(fieldModel, name = fieldId.name)
             if (!variableForField.hasDefaultValue())
                 setFieldValue(obj, fieldId, variableForField)
         }
@@ -259,9 +260,12 @@ open class CgVariableConstructor(val context: CgContext) :
         for (statementModel in model.modificationsChain) {
             when (statementModel) {
                 is UtDirectSetFieldModel -> {
-                    val instance = declareOrGet(statementModel.instance)
+                    val instance = getOrCreateVariable(statementModel.instance)
                     // fields here are supposed to be accessible, so we assign them directly without any checks
-                    instance[statementModel.fieldId] `=` declareOrGet(statementModel.fieldModel)
+                    instance[statementModel.fieldId] `=` getOrCreateVariable(
+                        model = statementModel.fieldModel,
+                        name = statementModel.fieldId.name,
+                    )
                 }
                 is UtStatementCallModel -> {
                     val call = createCgExecutableCallFromUtExecutableCall(statementModel)
@@ -284,23 +288,22 @@ open class CgVariableConstructor(val context: CgContext) :
         when (statementModel) {
             is UtExecutableCallModel -> {
                 val executable = statementModel.executable
+                val paramNames = runCatching {
+                    executable.executable.parameters.map { if (it.isNamePresent) it.name else null }
+                }.getOrNull()
                 val params = statementModel.params
+                val caller = statementModel.instance?.let { getOrCreateVariable(it) }
+                val args = params.mapIndexed { i, param ->
+                    getOrCreateVariable(param, name = paramNames?.getOrNull(i))
+                }
 
                 when (executable) {
-                    is MethodId -> {
-                        val caller = statementModel.instance?.let { declareOrGet(it) }
-                        val args = params.map { declareOrGet(it) }
-                        caller[executable](*args.toTypedArray())
-                    }
-
-                    is ConstructorId -> {
-                        val args = params.map { declareOrGet(it) }
-                        executable(*args.toTypedArray())
-                    }
+                    is MethodId -> caller[executable](*args.toTypedArray())
+                    is ConstructorId -> executable(*args.toTypedArray())
                 }
             }
             is UtDirectGetFieldModel -> {
-                val instance = declareOrGet(statementModel.instance)
+                val instance = getOrCreateVariable(statementModel.instance)
                 val fieldAccess = statementModel.fieldAccess
                 utilsClassId[getFieldValue](instance, fieldAccess.fieldId.declaringClass.canonicalName, fieldAccess.fieldId.name)
             }
@@ -508,13 +511,6 @@ open class CgVariableConstructor(val context: CgContext) :
         return newVar(Class::class.id, baseName) { init }
     }
 
-    /**
-     * Either declares a new variable or gets it from context's cache
-     * Returns the obtained variable
-     */
-    private fun declareOrGet(model: UtModel): CgValue =
-        valueByUtModelWrapper[model.wrap()] ?: getOrCreateVariable(model)
-
     private fun basicForLoop(start: Any, until: Any, body: (i: CgExpression) -> Unit) {
         forLoop {
             val (i, init) = loopInitialization(intClassId, "i", start.resolve())