diff --git a/src/main/groovy/com/netflix/gradle/plugins/application/OspackageApplicationSpringBootPlugin.groovy b/src/main/groovy/com/netflix/gradle/plugins/application/OspackageApplicationSpringBootPlugin.groovy
index 4c753b5d..6c565f52 100644
--- a/src/main/groovy/com/netflix/gradle/plugins/application/OspackageApplicationSpringBootPlugin.groovy
+++ b/src/main/groovy/com/netflix/gradle/plugins/application/OspackageApplicationSpringBootPlugin.groovy
@@ -17,6 +17,7 @@
 package com.netflix.gradle.plugins.application
 
 import groovy.transform.CompileDynamic
+import org.gradle.api.GradleException
 import org.gradle.api.Plugin
 import org.gradle.api.Project
 import org.gradle.api.distribution.plugins.DistributionPlugin
@@ -24,6 +25,7 @@ import org.gradle.api.invocation.Gradle
 import org.gradle.api.plugins.ApplicationPlugin
 import org.gradle.api.plugins.JavaPlugin
 import org.gradle.api.tasks.application.CreateStartScripts
+import org.gradle.tooling.BuildException
 import org.gradle.util.GradleVersion
 
 /**
@@ -75,15 +77,23 @@ class OspackageApplicationSpringBootPlugin implements Plugin<Project> {
                         }
                     }
                 }
-                try {
+
+                if(GradleVersion.current().baseVersion < GradleVersion.version('6.4').baseVersion) {
+                    // Allow the springBoot extension configuration to propagate to the application plugin
+                    if (project.application.mainClassName == null) {
+                        project.application.mainClassName = project.springBoot.mainClassName
+                    }
+                    if(!project.application.mainClassName) {
+                        throw new GradleException("mainClassName should be configured in order to generate a valid debian file. Ex. mainClassName = 'com.netflix.app.MyApp'")
+                    }
+                } else {
                     // Allow the springBoot extension configuration to propagate to the application plugin
                     if (!project.application.mainClass.isPresent()) {
                         project.application.mainClass.set(project.springBoot.mainClassName)
                     }
-                } catch (MissingPropertyException ignore) {
-                    // Releases prior to Gradle 6.4
-                    if (project.application.mainClassName == null) {
-                        project.application.mainClassName = project.springBoot.mainClassName
+
+                    if(!project.application.mainClass.isPresent()) {
+                        throw new GradleException("mainClass should be configured in order to generate a valid debian file. Ex. mainClass = 'com.netflix.app.MyApp'")
                     }
                 }
             }
diff --git a/src/test/groovy/com/netflix/gradle/plugins/application/OspackageApplicationSpringBootPluginLauncherSpec.groovy b/src/test/groovy/com/netflix/gradle/plugins/application/OspackageApplicationSpringBootPluginLauncherSpec.groovy
index 6e3927ca..e2b7b3b7 100644
--- a/src/test/groovy/com/netflix/gradle/plugins/application/OspackageApplicationSpringBootPluginLauncherSpec.groovy
+++ b/src/test/groovy/com/netflix/gradle/plugins/application/OspackageApplicationSpringBootPluginLauncherSpec.groovy
@@ -19,9 +19,15 @@ package com.netflix.gradle.plugins.application
 import com.google.common.base.Throwables
 import com.netflix.gradle.plugins.deb.Scanner
 import nebula.test.IntegrationSpec
+import org.junit.Rule
+import org.junit.contrib.java.lang.system.ProvideSystemProperty
 import spock.lang.Unroll
 
 class OspackageApplicationSpringBootPluginLauncherSpec extends IntegrationSpec {
+
+    @Rule
+    public final ProvideSystemProperty ignoreDeprecations = new ProvideSystemProperty("ignoreDeprecations", "true")
+
     def 'plugin throws exception if spring-boot plugin not applied'() {
         buildFile << """
             ${applyPlugin(OspackageApplicationSpringBootPlugin)}
@@ -180,4 +186,48 @@ class OspackageApplicationSpringBootPluginLauncherSpec extends IntegrationSpec {
         bootVersion | fileMode
         '2.4.2'     | 493
     }
+
+    @Unroll
+    def 'application fails if mainClass is not present'() {
+        final applicationDir = "$moduleName-boot"
+        final startScript = file("build/install/$applicationDir/bin/$moduleName")
+
+        buildFile << buildScript(bootVersion, startScript)
+        buildFile << """
+        mainClassName = null
+        mainClass.set(null)
+        """
+
+        when:
+        def result = runTasksWithFailure('runStartScript')
+
+        then:
+        result.standardError.contains("mainClass should be configured in order to generate a valid debian file. Ex. mainClass = 'com.netflix.app.MyApp'")
+
+        where:
+        bootVersion | _
+        '2.4.2'     | _
+    }
+
+    @Unroll
+    def 'application fails if mainClassName is not present (old versions of Gradle)'() {
+        final applicationDir = "$moduleName-boot"
+        final startScript = file("build/install/$applicationDir/bin/$moduleName")
+
+        gradleVersion = '6.3'
+        buildFile << buildScript(bootVersion, startScript)
+        buildFile << """
+        mainClassName = null
+        """
+
+        when:
+        def result = runTasksWithFailure('runStartScript')
+
+        then:
+        result.standardError.contains("mainClassName should be configured in order to generate a valid debian file. Ex. mainClassName = 'com.netflix.app.MyApp'")
+
+        where:
+        bootVersion | _
+        '2.4.2'     | _
+    }
 }