diff --git a/modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/tasks/ValidateTask.kt b/modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/tasks/ValidateTask.kt
index 3d0cbab2b064..6f3038e4e29c 100644
--- a/modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/tasks/ValidateTask.kt
+++ b/modules/openapi-generator-gradle-plugin/src/main/kotlin/org/openapitools/generator/gradle/plugin/tasks/ValidateTask.kt
@@ -56,11 +56,11 @@ import org.openapitools.codegen.validations.oas.RuleConfiguration
 open class ValidateTask : DefaultTask() {
     @get:InputFile
     @PathSensitive(PathSensitivity.RELATIVE)
-    var inputSpec = project.objects.property<String>()
+    val inputSpec = project.objects.property<String>()
 
     @Optional
     @Input
-    var recommend = project.objects.property<Boolean?>()
+    val recommend = project.objects.property<Boolean?>()
 
     @Suppress("unused")
     @get:Internal
@@ -128,4 +128,4 @@ open class ValidateTask : DefaultTask() {
             out.println("Spec is valid.")
         }
     }
-}
\ No newline at end of file
+}
diff --git a/modules/openapi-generator-gradle-plugin/src/test/kotlin/ValidateTaskDslTest.kt b/modules/openapi-generator-gradle-plugin/src/test/kotlin/ValidateTaskDslTest.kt
index 2b06e853192e..94ae68ab3af8 100644
--- a/modules/openapi-generator-gradle-plugin/src/test/kotlin/ValidateTaskDslTest.kt
+++ b/modules/openapi-generator-gradle-plugin/src/test/kotlin/ValidateTaskDslTest.kt
@@ -3,6 +3,8 @@ package org.openapitools.generator.gradle.plugin
 import org.gradle.testkit.runner.GradleRunner
 import org.gradle.testkit.runner.TaskOutcome.FAILED
 import org.gradle.testkit.runner.TaskOutcome.SUCCESS
+import org.gradle.util.GradleVersion
+import org.testng.annotations.DataProvider
 import org.testng.annotations.Test
 import java.io.File
 import kotlin.test.assertEquals
@@ -11,8 +13,25 @@ import kotlin.test.assertTrue
 class ValidateTaskDslTest : TestBase() {
     override var temp: File = createTempDir(javaClass.simpleName)
 
-    @Test
-    fun `openApiValidate should fail on non-file spec`() {
+    @DataProvider(name = "gradle_version_provider")
+    fun gradleVersionProvider(): Array<Array<String?>> = arrayOf(
+        arrayOf(null), // uses the version of Gradle used to build the plugin itself
+        arrayOf("5.6.4"),
+        arrayOf("6.9"),
+        arrayOf("7.0"))
+
+    private fun getGradleRunner(gradleVersion: String?): GradleRunner {
+        val gradleRunner = GradleRunner.create()
+        return if (gradleVersion.isNullOrBlank()) {
+            //Use the current version of Gradle
+            gradleRunner
+        } else {
+            gradleRunner.withGradleVersion(gradleVersion)
+        }
+    }
+
+    @Test(dataProvider = "gradle_version_provider")
+    fun `openApiValidate should fail on non-file spec`(gradleVersion: String?) {
         // Arrange
         withProject("""
             | plugins {
@@ -25,20 +44,28 @@ class ValidateTaskDslTest : TestBase() {
         """.trimMargin())
 
         // Act
-        val result = GradleRunner.create()
+        val result = getGradleRunner(gradleVersion)
                 .withProjectDir(temp)
                 .withArguments("openApiValidate")
                 .withPluginClasspath()
                 .buildAndFail()
 
         // Assert
-        assertTrue(result.output.contains("some_location' specified for property 'inputSpec' does not exist"), "Unexpected/no message presented to the user for a spec pointing to an invalid URI.")
+        val gradleActualVersion = gradleVersion ?: GradleVersion.current().version
+        val gradleVersionParts = gradleActualVersion.split(".")
+        val isBeforeGradle7 = (gradleVersionParts.isEmpty() || gradleVersionParts[0].toInt() < 7)
+        val expectedMessage = if (isBeforeGradle7) {
+            "some_location' specified for property 'inputSpec' does not exist"
+        } else {
+            "An input file was expected to be present but it doesn't exist."
+        }
+        assertTrue(result.output.contains(expectedMessage), "Unexpected/no message presented to the user for a spec pointing to an invalid URI.")
         assertEquals(FAILED, result.task(":openApiValidate")?.outcome,
                 "Expected a failed run, but found ${result.task(":openApiValidate")?.outcome}")
     }
 
-    @Test
-    fun `openApiValidate should succeed on valid spec`() {
+    @Test(dataProvider = "gradle_version_provider")
+    fun `openApiValidate should succeed on valid spec`(gradleVersion: String?) {
         // Arrange
         val projectFiles = mapOf(
                 "spec.yaml" to javaClass.classLoader.getResourceAsStream("specs/petstore-v3.0.yaml")
@@ -55,7 +82,7 @@ class ValidateTaskDslTest : TestBase() {
         """.trimMargin(), projectFiles)
 
         // Act
-        val result = GradleRunner.create()
+        val result = getGradleRunner(gradleVersion)
                 .withProjectDir(temp)
                 .withArguments("openApiValidate")
                 .withPluginClasspath()
@@ -67,8 +94,8 @@ class ValidateTaskDslTest : TestBase() {
                 "Expected a successful run, but found ${result.task(":openApiValidate")?.outcome}")
     }
 
-    @Test
-    fun `openApiValidate should fail on invalid spec`() {
+    @Test(dataProvider = "gradle_version_provider")
+    fun `openApiValidate should fail on invalid spec`(gradleVersion: String?) {
         // Arrange
         val projectFiles = mapOf(
                 "spec.yaml" to javaClass.classLoader.getResourceAsStream("specs/petstore-v3.0-invalid.yaml")
@@ -84,7 +111,7 @@ class ValidateTaskDslTest : TestBase() {
         """.trimMargin(), projectFiles)
 
         // Act
-        val result = GradleRunner.create()
+        val result = getGradleRunner(gradleVersion)
                 .withProjectDir(temp)
                 .withArguments("openApiValidate")
                 .withPluginClasspath()
@@ -96,4 +123,4 @@ class ValidateTaskDslTest : TestBase() {
                 "Expected a failed run, but found ${result.task(":openApiValidate")?.outcome}")
     }
 
-}
\ No newline at end of file
+}