diff --git a/utbot-framework-test/src/test/kotlin/org/utbot/examples/collections/CustomerExamplesTest.kt b/utbot-framework-test/src/test/kotlin/org/utbot/examples/collections/CustomerExamplesTest.kt
index 5723e045dd..33d51fcd0e 100644
--- a/utbot-framework-test/src/test/kotlin/org/utbot/examples/collections/CustomerExamplesTest.kt
+++ b/utbot-framework-test/src/test/kotlin/org/utbot/examples/collections/CustomerExamplesTest.kt
@@ -16,7 +16,7 @@ internal class CustomerExamplesTest: UtValueTestCaseChecker(
     testClass = CustomerExamples::class,
     testCodeGeneration = true,
     pipelines = listOf(
-        TestLastStage(CodegenLanguage.JAVA, lastStage = TestExecution, parameterizedModeLastStage = Compilation),
+        TestLastStage(CodegenLanguage.JAVA, lastStage = TestExecution),
         TestLastStage(CodegenLanguage.KOTLIN, lastStage = CodeGeneration)
     )
 ) {
diff --git a/utbot-framework-test/src/test/kotlin/org/utbot/examples/mixed/PrivateConstructorExampleTest.kt b/utbot-framework-test/src/test/kotlin/org/utbot/examples/mixed/PrivateConstructorExampleTest.kt
index 7cda4f638a..79662edf90 100644
--- a/utbot-framework-test/src/test/kotlin/org/utbot/examples/mixed/PrivateConstructorExampleTest.kt
+++ b/utbot-framework-test/src/test/kotlin/org/utbot/examples/mixed/PrivateConstructorExampleTest.kt
@@ -7,18 +7,11 @@ import org.utbot.framework.plugin.api.CodegenLanguage
 import org.utbot.testcheckers.eq
 import org.utbot.tests.infrastructure.Compilation
 
-// TODO parameterized tests disabled due to https://github.com/UnitTestBot/UTBotJava/issues/1266
 internal class PrivateConstructorExampleTest : UtValueTestCaseChecker(
     testClass = PrivateConstructorExample::class,
     pipelines = listOf(
-        TestLastStage(
-            CodegenLanguage.JAVA,
-            parameterizedModeLastStage = Compilation
-        ),
-        TestLastStage(
-            CodegenLanguage.KOTLIN,
-            parameterizedModeLastStage = Compilation
-        )
+        TestLastStage(CodegenLanguage.JAVA),
+        TestLastStage(CodegenLanguage.KOTLIN)
     )
 ) {
 
diff --git a/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/constructor/tree/CgMethodConstructor.kt b/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/constructor/tree/CgMethodConstructor.kt
index 10e83236ca..d20af2483e 100644
--- a/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/constructor/tree/CgMethodConstructor.kt
+++ b/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/constructor/tree/CgMethodConstructor.kt
@@ -1487,9 +1487,8 @@ open class CgMethodConstructor(val context: CgContext) : CgContextOwner by conte
                     substituteStaticFields(statics, isParametrized = true)
 
                     // build this instance
-                    thisInstance =
-                        genericExecution.stateBefore.thisInstance?.let {
-                        variableConstructor.getOrCreateVariable(it)
+                    thisInstance = genericExecution.stateBefore.thisInstance?.let {
+                        currentMethodParameters[CgParameterKind.ThisInstance]
                     }
 
                     // build arguments for method under test and parameterized test
@@ -1552,6 +1551,20 @@ open class CgMethodConstructor(val context: CgContext) : CgContextOwner by conte
         val executableUnderTestParameters = testSet.executableId.executable.parameters
 
         return mutableListOf<CgParameterDeclaration>().apply {
+            // this instance
+            genericExecution.stateBefore.thisInstance?.let {
+                val type = wrapTypeIfRequired(it.classId)
+                val thisInstance = CgParameterDeclaration(
+                    parameter = declareParameter(
+                        type = type,
+                        name = nameGenerator.variableName(type)
+                    ),
+                    isReferenceType = true
+                )
+                this += thisInstance
+                currentMethodParameters[CgParameterKind.ThisInstance] = thisInstance.parameter
+            }
+
             // arguments
             for (index in genericExecution.stateBefore.parameters.indices) {
                 val argumentName = paramNames[executableUnderTest]?.get(index)
@@ -1663,6 +1676,10 @@ open class CgMethodConstructor(val context: CgContext) : CgContextOwner by conte
     private fun createExecutionArguments(testSet: CgMethodTestSet, execution: UtExecution): List<CgExpression> {
         val arguments = mutableListOf<CgExpression>()
 
+        execution.stateBefore.thisInstance?.let {
+            arguments += variableConstructor.getOrCreateVariable(it)
+        }
+
         for ((paramIndex, paramModel) in execution.stateBefore.parameters.withIndex()) {
             val argumentName = paramNames[testSet.executableId]?.get(paramIndex)
             arguments += variableConstructor.getOrCreateVariable(paramModel, argumentName)
@@ -1673,7 +1690,6 @@ open class CgMethodConstructor(val context: CgContext) : CgContextOwner by conte
             arguments += variableConstructor.getOrCreateVariable(model, field.name)
         }
 
-
         val method = currentExecutable!!
         val needsReturnValue = method.returnType != voidClassId
         val containsFailureExecution = containsFailureExecution(testSet)
diff --git a/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/tree/CgElement.kt b/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/tree/CgElement.kt
index 05c5c494a4..b52cd625b7 100644
--- a/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/tree/CgElement.kt
+++ b/utbot-framework/src/main/kotlin/org/utbot/framework/codegen/model/tree/CgElement.kt
@@ -728,6 +728,7 @@ data class CgParameterDeclaration(
  * - exception expected from MUT with the given arguments
  */
 sealed class CgParameterKind {
+    object ThisInstance : CgParameterKind()
     data class Argument(val index: Int) : CgParameterKind()
     data class Statics(val model: UtModel) : CgParameterKind()
     object ExpectedResult : CgParameterKind()