diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildDockerTask.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildDockerTask.java
index 692449db03..99ae393dab 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildDockerTask.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildDockerTask.java
@@ -111,7 +111,8 @@ public void buildDocker()
             getProject(),
             getLogger(),
             tempDirectoryProvider,
-            jibExtension.getConfigurationName().get());
+            jibExtension.getConfigurationName().get(),
+            jibExtension.getSourceSetName().get());
     GlobalConfig globalConfig = GlobalConfig.readConfig();
     Future<Optional<String>> updateCheckFuture =
         TaskCommon.newUpdateChecker(projectProperties, globalConfig, getLogger());
diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildImageTask.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildImageTask.java
index 49265559a6..d4a317fad2 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildImageTask.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildImageTask.java
@@ -99,7 +99,8 @@ public void buildImage()
             getProject(),
             getLogger(),
             tempDirectoryProvider,
-            jibExtension.getConfigurationName().get());
+            jibExtension.getConfigurationName().get(),
+            jibExtension.getSourceSetName().get());
     GlobalConfig globalConfig = GlobalConfig.readConfig();
     Future<Optional<String>> updateCheckFuture =
         TaskCommon.newUpdateChecker(projectProperties, globalConfig, getLogger());
diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildTarTask.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildTarTask.java
index 1a77856b6b..d770b92832 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildTarTask.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/BuildTarTask.java
@@ -94,7 +94,10 @@ public FileCollection getInputFiles() {
             .map(ExtraDirectoryParameters::getFrom)
             .collect(Collectors.toList());
     return GradleProjectProperties.getInputFiles(
-        getProject(), extraDirectories, jibExtension.getConfigurationName().get());
+        getProject(),
+        extraDirectories,
+        jibExtension.getConfigurationName().get(),
+        jibExtension.getSourceSetName().get());
   }
 
   /**
@@ -130,7 +133,8 @@ public void buildTar()
             getProject(),
             getLogger(),
             tempDirectoryProvider,
-            jibExtension.getConfigurationName().get());
+            jibExtension.getConfigurationName().get(),
+            jibExtension.getSourceSetName().get());
     GlobalConfig globalConfig = GlobalConfig.readConfig();
     Future<Optional<String>> updateCheckFuture =
         TaskCommon.newUpdateChecker(projectProperties, globalConfig, getLogger());
diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/GradleProjectProperties.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/GradleProjectProperties.java
index 6a1978fe19..28ce73a8ef 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/GradleProjectProperties.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/GradleProjectProperties.java
@@ -94,9 +94,6 @@ public class GradleProjectProperties implements ProjectProperties {
   /** Used for logging during main class inference. */
   private static final String JAR_PLUGIN_NAME = "'jar' task";
 
-  /** Name of the `main` {@link SourceSet} to use as source files. */
-  private static final String MAIN_SOURCE_SET_NAME = "main";
-
   private static final Duration LOGGING_THREAD_SHUTDOWN_TIMEOUT = Duration.ofSeconds(1);
 
   /**
@@ -107,13 +104,15 @@ public class GradleProjectProperties implements ProjectProperties {
    * @param tempDirectoryProvider for scratch space during the build
    * @param configurationName the configuration of which the dependencies should be packed into the
    *     container
+   * @param sourceSetName the name of the source set which should be packed into the container
    * @return a GradleProjectProperties instance to use in a jib build
    */
   public static GradleProjectProperties getForProject(
       Project project,
       Logger logger,
       TempDirectoryProvider tempDirectoryProvider,
-      String configurationName) {
+      String configurationName,
+      String sourceSetName) {
     Supplier<List<JibGradlePluginExtension<?>>> extensionLoader =
         () -> {
           List<JibGradlePluginExtension<?>> extensions = new ArrayList<>();
@@ -124,7 +123,7 @@ public static GradleProjectProperties getForProject(
           return extensions;
         };
     return new GradleProjectProperties(
-        project, logger, tempDirectoryProvider, extensionLoader, configurationName);
+        project, logger, tempDirectoryProvider, extensionLoader, configurationName, sourceSetName);
   }
 
   String getWarFilePath() {
@@ -163,6 +162,7 @@ private static boolean isProgressFooterEnabled(Project project) {
   private final TempDirectoryProvider tempDirectoryProvider;
   private final Supplier<List<JibGradlePluginExtension<?>>> extensionLoader;
   private final String configurationName;
+  private final String sourceSetName;
 
   @VisibleForTesting
   GradleProjectProperties(
@@ -170,11 +170,13 @@ private static boolean isProgressFooterEnabled(Project project) {
       Logger logger,
       TempDirectoryProvider tempDirectoryProvider,
       Supplier<List<JibGradlePluginExtension<?>>> extensionLoader,
-      String configurationName) {
+      String configurationName,
+      String sourceSetName) {
     this.project = project;
     this.tempDirectoryProvider = tempDirectoryProvider;
     this.extensionLoader = extensionLoader;
     this.configurationName = configurationName;
+    this.sourceSetName = sourceSetName;
     ConsoleLoggerBuilder consoleLoggerBuilder =
         (isProgressFooterEnabled(project)
                 ? ConsoleLoggerBuilder.rich(singleThreadedExecutor, false)
@@ -409,14 +411,17 @@ public boolean isWarProject() {
    */
   @VisibleForTesting
   static FileCollection getInputFiles(
-      Project project, List<Path> extraDirectories, String configurationName) {
+      Project project,
+      List<Path> extraDirectories,
+      String configurationName,
+      String sourceSetName) {
     List<FileCollection> dependencyFileCollections = new ArrayList<>();
     dependencyFileCollections.add(project.getConfigurations().getByName(configurationName));
     // Output directories (classes and resources) from main SourceSet are added
     // so that BuildTarTask picks up changes in these and do not skip task
     SourceSetContainer sourceSetContainer =
         project.getExtensions().getByType(SourceSetContainer.class);
-    SourceSet mainSourceSet = sourceSetContainer.getByName(MAIN_SOURCE_SET_NAME);
+    SourceSet mainSourceSet = sourceSetContainer.getByName(sourceSetName);
     dependencyFileCollections.add(mainSourceSet.getOutput());
 
     extraDirectories.stream()
@@ -547,6 +552,6 @@ private JibGradlePluginExtension<?> findConfiguredExtension(
   private SourceSet getMainSourceSet() {
     SourceSetContainer sourceSetContainer =
         project.getExtensions().getByType(SourceSetContainer.class);
-    return sourceSetContainer.getByName(MAIN_SOURCE_SET_NAME);
+    return sourceSetContainer.getByName(sourceSetName);
   }
 }
diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibExtension.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibExtension.java
index fbcea4c006..7089cc39e6 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibExtension.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibExtension.java
@@ -27,6 +27,7 @@
 import org.gradle.api.tasks.Input;
 import org.gradle.api.tasks.Nested;
 import org.gradle.api.tasks.Optional;
+import org.gradle.api.tasks.SourceSet;
 
 /**
  * Plugin extension for {@link JibPlugin}.
@@ -96,6 +97,7 @@ public class JibExtension {
   private final Property<Boolean> allowInsecureRegistries;
   private final Property<String> containerizingMode;
   private final Property<String> configurationName;
+  private final Property<String> sourceSetName;
   private final ListProperty<ExtensionParameters> pluginExtensions;
   private final ExtensionParametersSpec extensionParametersSpec;
 
@@ -126,6 +128,7 @@ public JibExtension(Project project) {
         objectFactory
             .property(String.class)
             .convention(JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME);
+    sourceSetName = objectFactory.property(String.class).convention(SourceSet.MAIN_SOURCE_SET_NAME);
   }
 
   public void from(Action<? super BaseImageParameters> action) {
@@ -241,6 +244,16 @@ public Property<String> getConfigurationName() {
     return configurationName;
   }
 
+  @Input
+  @Optional
+  public Property<String> getSourceSetName() {
+    String property = System.getProperty(PropertyNames.SOURCE_SET_NAME);
+    if (property != null && !property.equals(sourceSetName.get())) {
+      sourceSetName.set(property);
+    }
+    return sourceSetName;
+  }
+
   @Nested
   @Optional
   public ListProperty<ExtensionParameters> getPluginExtensions() {
diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibPlugin.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibPlugin.java
index 6f2d9d16d1..904b649f9c 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibPlugin.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/JibPlugin.java
@@ -186,7 +186,7 @@ public void apply(Project project) {
               projectAfterEvaluation
                   .getExtensions()
                   .getByType(SourceSetContainer.class)
-                  .getByName(SourceSet.MAIN_SOURCE_SET_NAME);
+                  .getByName(jibExtension.getSourceSetName().get());
           jibDependencies.add(mainSourceSet.getRuntimeClasspath());
           jibDependencies.add(
               projectAfterEvaluation
diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/FilesTaskV2.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/FilesTaskV2.java
index fc15b021cf..80900e30e7 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/FilesTaskV2.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/FilesTaskV2.java
@@ -158,14 +158,17 @@ private void addGradleFiles(Project project) {
    * @param project the project
    */
   private void addProjectFiles(Project project) {
+    Preconditions.checkNotNull(jibExtension);
+
     // Add build config, settings, etc.
     addGradleFiles(project);
 
     // Add sources + resources
     SourceSetContainer sourceSetContainer =
         project.getExtensions().findByType(SourceSetContainer.class);
+    String sourceSetName = jibExtension.getSourceSetName().get();
     if (sourceSetContainer != null) {
-      SourceSet mainSourceSet = sourceSetContainer.findByName(SourceSet.MAIN_SOURCE_SET_NAME);
+      SourceSet mainSourceSet = sourceSetContainer.findByName(sourceSetName);
       if (mainSourceSet != null) {
         mainSourceSet
             .getAllSource()
diff --git a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/SyncMapTask.java b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/SyncMapTask.java
index 7d8d9e4b02..df2fd7a2bf 100644
--- a/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/SyncMapTask.java
+++ b/jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/SyncMapTask.java
@@ -55,7 +55,8 @@ public void listFilesAndTargets() {
               getProject(),
               getLogger(),
               tempDirectoryProvider,
-              jibExtension.getConfigurationName().get());
+              jibExtension.getConfigurationName().get(),
+              jibExtension.getSourceSetName().get());
 
       GradleRawConfiguration configuration = new GradleRawConfiguration(jibExtension);
 
diff --git a/jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleProjectPropertiesExtensionTest.java b/jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleProjectPropertiesExtensionTest.java
index 63718ce0e5..6959fe7f7d 100644
--- a/jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleProjectPropertiesExtensionTest.java
+++ b/jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleProjectPropertiesExtensionTest.java
@@ -40,6 +40,7 @@
 import org.gradle.api.logging.configuration.ConsoleOutput;
 import org.gradle.api.model.ObjectFactory;
 import org.gradle.api.plugins.JavaPlugin;
+import org.gradle.api.tasks.SourceSet;
 import org.hamcrest.CoreMatchers;
 import org.hamcrest.MatcherAssert;
 import org.junit.Assert;
@@ -238,7 +239,8 @@ public void setUp() {
             mockLogger,
             mockTempDirectoryProvider,
             () -> loadedExtensions,
-            JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME);
+            JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME,
+            SourceSet.MAIN_SOURCE_SET_NAME);
   }
 
   @Test
diff --git a/jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleProjectPropertiesTest.java b/jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleProjectPropertiesTest.java
index 7698228ab0..7618e8a5c9 100644
--- a/jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleProjectPropertiesTest.java
+++ b/jib-gradle-plugin/src/test/java/com/google/cloud/tools/jib/gradle/GradleProjectPropertiesTest.java
@@ -69,6 +69,7 @@
 import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.provider.Property;
+import org.gradle.api.tasks.SourceSet;
 import org.gradle.api.tasks.bundling.War;
 import org.gradle.jvm.tasks.Jar;
 import org.gradle.testfixtures.ProjectBuilder;
@@ -168,7 +169,8 @@ public void setUp() throws URISyntaxException, IOException {
             mockLogger,
             mockTempDirectoryProvider,
             mockExtensionLoader,
-            JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME);
+            JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME,
+            SourceSet.MAIN_SOURCE_SET_NAME);
   }
 
   @Test
@@ -219,7 +221,10 @@ public void testGetInputFiles() throws URISyntaxException {
     List<Path> extraDirectories = Arrays.asList(applicationDirectory.resolve("extra-directory"));
     FileCollection fileCollection =
         GradleProjectProperties.getInputFiles(
-            project, extraDirectories, JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME);
+            project,
+            extraDirectories,
+            JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME,
+            SourceSet.MAIN_SOURCE_SET_NAME);
 
     assertThat(fileCollection)
         .comparingElementsUsing(FILE_PATH_OF)
@@ -341,7 +346,8 @@ public void testCreateContainerBuilder_noClassesFiles()
             mockLogger,
             mockTempDirectoryProvider,
             mockExtensionLoader,
-            JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME);
+            JavaPlugin.RUNTIME_CLASSPATH_CONFIGURATION_NAME,
+            SourceSet.MAIN_SOURCE_SET_NAME);
 
     gradleProjectProperties.createJibContainerBuilder(
         JavaContainerBuilder.from(RegistryImage.named("base")), ContainerizingMode.EXPLODED);
diff --git a/jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/PropertyNames.java b/jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/PropertyNames.java
index 14e27c2ed3..e660da5d7c 100644
--- a/jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/PropertyNames.java
+++ b/jib-plugins-common/src/main/java/com/google/cloud/tools/jib/plugins/common/PropertyNames.java
@@ -59,6 +59,7 @@ public class PropertyNames {
   public static final String OUTPUT_PATHS_TAR = "jib.outputPaths.tar";
   public static final String CONTAINERIZING_MODE = "jib.containerizingMode";
   public static final String CONFIGURATION_NAME = "jib.configurationName";
+  public static final String SOURCE_SET_NAME = "jib.sourceSetName";
   public static final String SKIP = "jib.skip";
 
   public static final String CONTAINERIZE = "jib.containerize";