diff --git a/src/main/java/com/google/devtools/build/lib/packages/Package.java b/src/main/java/com/google/devtools/build/lib/packages/Package.java
index b5409285759896..598a05b59121c3 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/Package.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/Package.java
@@ -1370,7 +1370,7 @@ FailureDetail getFailureDetail() {
       return null;
     }
 
-    Builder setStarlarkFileDependencies(ImmutableList<Label> starlarkFileDependencies) {
+    public Builder setStarlarkFileDependencies(ImmutableList<Label> starlarkFileDependencies) {
       this.starlarkFileDependencies = starlarkFileDependencies;
       return this;
     }
diff --git a/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java b/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
index b0e956743c53c2..9cd3424641c9ee 100644
--- a/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
+++ b/src/main/java/com/google/devtools/build/lib/packages/PackageFactory.java
@@ -706,7 +706,7 @@ private static ImmutableList<Label> transitiveClosureOfLabels(
     return ImmutableList.copyOf(set);
   }
 
-  private static void transitiveClosureOfLabelsRec(
+  public static void transitiveClosureOfLabelsRec(
       Set<Label> set, ImmutableMap<String, Module> loads) {
     for (Module m : loads.values()) {
       BazelModuleContext ctx = BazelModuleContext.of(m);
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java
index 9021c952a319e8..e9a55dcfe91c60 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunction.java
@@ -24,6 +24,7 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSortedSet;
+import com.google.common.collect.Sets;
 import com.google.devtools.build.lib.actions.FileValue;
 import com.google.devtools.build.lib.analysis.BlazeDirectories;
 import com.google.devtools.build.lib.cmdline.Label;
@@ -58,6 +59,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Set;
 import net.starlark.java.eval.Module;
 import net.starlark.java.eval.Mutability;
 import net.starlark.java.eval.Starlark;
@@ -325,14 +327,21 @@ public SkyValue compute(SkyKey skyKey, Environment env)
               directories.getWorkspace(),
               directories.getLocalJavabase(),
               starlarkSemantics);
+      Set<Label> starlarkFileDependencies;
       if (prevValue != null) {
+        starlarkFileDependencies = Sets.newLinkedHashSet(prevValue.getPackage()
+            .getStarlarkFileDependencies());
         try {
           parser.setParent(
               prevValue.getPackage(), prevValue.getLoadedModules(), prevValue.getBindings());
         } catch (NameConflictException e) {
           throw new WorkspaceFileFunctionException(e, Transience.PERSISTENT);
         }
+      } else {
+        starlarkFileDependencies = Sets.newLinkedHashSet();
       }
+      PackageFactory.transitiveClosureOfLabelsRec(starlarkFileDependencies, loadedModules);
+      builder.setStarlarkFileDependencies(ImmutableList.copyOf(starlarkFileDependencies));
       // Execute the partial files that comprise this chunk.
       for (StarlarkFile partialFile : chunk) {
         parser.execute(partialFile, loadedModules, key);
diff --git a/src/test/py/bazel/query_test.py b/src/test/py/bazel/query_test.py
index d5b37fa8fa5781..c8a4c425922cd5 100644
--- a/src/test/py/bazel/query_test.py
+++ b/src/test/py/bazel/query_test.py
@@ -38,6 +38,84 @@ def testSimpleQuery(self):
     self._AssertQueryOutput('deps(//foo:top-rule, 1)', '//foo:top-rule',
                             '//foo:dep-rule')
 
+  def testBuildFilesForExternalRepos_Simple(self):
+    self.ScratchFile('WORKSPACE', [
+      'load("//:deps.bzl", "repos")',
+      'repos()',
+    ])
+    self.ScratchFile('BUILD.bazel')
+    self.ScratchFile('deps.bzl', [
+      'def repos():',
+      '    native.new_local_repository(',
+      '        name = "io_bazel_rules_go",',
+      '        path = ".",',
+      """        build_file_content = "exports_files(glob(['*.go']))",""",
+      '    )',
+    ])
+    self._AssertQueryOutputContains('buildfiles(//external:io_bazel_rules_go)',
+                            '//external:WORKSPACE', '//:deps.bzl', '//:BUILD.bazel')
+
+  def testBuildFilesForExternalRepos_IndirectLoads(self):
+    self.ScratchFile('WORKSPACE', [
+      'load("//:deps.bzl", "repos")',
+      'repos()',
+    ])
+    self.ScratchFile('BUILD.bazel')
+    self.ScratchFile('deps.bzl', [
+      'load("//:private_deps.bzl", "other_repos")',
+      'def repos():',
+      '    native.new_local_repository(',
+      '        name = "io_bazel_rules_go",',
+      '        path = ".",',
+      """        build_file_content = "exports_files(glob(['*.go']))",""",
+      '    )',
+      '    other_repos()',
+      '',
+    ])
+    self.ScratchFile('private_deps.bzl', [
+      'def other_repos():',
+      '    native.new_local_repository(',
+      '        name = "io_bazel_rules_python",',
+      '        path = ".",',
+      """        build_file_content = "exports_files(glob(['*.py']))",""",
+      '    )',
+    ])
+
+    self._AssertQueryOutputContains('buildfiles(//external:io_bazel_rules_python)',
+                            '//external:WORKSPACE', '//:deps.bzl', '//:private_deps.bzl', '//:BUILD.bazel')
+
+  def testBuildFilesForExternalRepos_NoDuplicates(self):
+    self.ScratchFile('WORKSPACE', [
+      'load("//:deps.bzl", "repos")',
+      'repos()',
+    ])
+    self.ScratchFile('BUILD.bazel')
+    self.ScratchFile('deps.bzl', [
+      'def repos():',
+      '    native.new_local_repository(',
+      '        name = "io_bazel_rules_go",',
+      '        path = ".",',
+      """        build_file_content = "exports_files(glob(['*.go']))",""",
+      '    )',
+      '    other_repos()',
+      '',
+      'def other_repos():',
+      '    native.new_local_repository(',
+      '        name = "io_bazel_rules_python",',
+      '        path = ".",',
+      """        build_file_content = "exports_files(glob(['*.py']))",""",
+      '    )',
+    ])
+
+    exit_code, stdout, stderr = self.RunBazel(['query', 'buildfiles(//external:io_bazel_rules_python)'])
+    self.AssertExitCode(exit_code, 0, stderr)
+    result = set()
+    for item in stdout:
+      if not item:
+        continue
+      self.assertNotIn(item, result)
+      result.add(item)
+
   def _AssertQueryOutput(self, query_expr, *expected_results):
     exit_code, stdout, stderr = self.RunBazel(['query', query_expr])
     self.AssertExitCode(exit_code, 0, stderr)
@@ -46,6 +124,14 @@ def _AssertQueryOutput(self, query_expr, *expected_results):
     self.assertEqual(len(stdout), len(expected_results))
     self.assertListEqual(stdout, sorted(expected_results))
 
+  def _AssertQueryOutputContains(self, query_expr, *expected_content):
+    exit_code, stdout, stderr = self.RunBazel(['query', query_expr])
+    self.AssertExitCode(exit_code, 0, stderr)
+
+    stdout = {x for x in stdout if x}
+    for item in expected_content:
+      self.assertIn(item, stdout)
+
 
 if __name__ == '__main__':
   unittest.main()