diff --git a/src/main/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibrary.java b/src/main/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibrary.java
index 8f44434..5933d06 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibrary.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibrary.java
@@ -31,7 +31,7 @@
 
   @Override
   public ConfiguredTarget create(RuleContext ruleContext) throws ActionConflictException {
-    ProtoInfo protoInfo = ProtoCommon.createProtoInfo(ruleContext, true);
+    ProtoInfo protoInfo = ProtoCommon.createProtoInfo(ruleContext);
     if (ruleContext.hasErrors()) {
       return null;
     }
diff --git a/src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCommon.java b/src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCommon.java
index 195ca3d..1463bbf 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCommon.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/proto/ProtoCommon.java
@@ -194,22 +194,29 @@
   // TODO(lberki): This should really be a PathFragment. Unfortunately, it's on the Starlark API of
   // ProtoInfo so it's not an easy change :(
   @Nullable
-  private static Library createLibraryWithoutVirtualSourceRoot(
+  private static Library getProtoSourceRoot(
       RuleContext ruleContext, ImmutableList<Artifact> directSources) {
-    String protoSourceRoot =
+    String protoSourceRoot = computeEffectiveProtoSourceRoot(ruleContext);
+    if (ruleContext.hasErrors()) {
+      return null;
+    }
+
+    // This is the same as getPackageIdentifier().getPathUnderExecRoot() due to the check above for
+    // protoSourceRoot == package name, but it's a bit more future-proof.
+    String result =
         ruleContext
             .getLabel()
             .getPackageIdentifier()
             .getRepository()
             .getPathUnderExecRoot()
+            .getRelative(protoSourceRoot)
             .getPathString();
 
     ImmutableList.Builder<Pair<Artifact, String>> builder = ImmutableList.builder();
     for (Artifact protoSource : directSources) {
       builder.add(new Pair<Artifact, String>(protoSource, null));
     }
-    return new Library(
-        directSources, protoSourceRoot.isEmpty() ? "." : protoSourceRoot, builder.build());
+    return new Library(directSources, result.isEmpty() ? "." : result, builder.build());
   }
 
   private static PathFragment getPathFragmentAttribute(
@@ -236,36 +243,18 @@
    * Returns the {@link Library} representing this <code>proto_library</code> rule if import prefix
    * munging is done. Otherwise, returns null.
    */
-  private static Library createLibraryWithVirtualSourceRootMaybe(
-      RuleContext ruleContext,
-      ImmutableList<Artifact> protoSources,
-      boolean virtualImportsWithGeneratedProtoFiles) {
+  private static Library createVirtualImportDirectoryMaybe(
+      RuleContext ruleContext, ImmutableList<Artifact> protoSources) {
     PathFragment importPrefixAttribute = getPathFragmentAttribute(ruleContext, "import_prefix");
     PathFragment stripImportPrefixAttribute =
         getPathFragmentAttribute(ruleContext, "strip_import_prefix");
-    PathFragment protoSourceRootAttribute =
-        getPathFragmentAttribute(ruleContext, "proto_source_root");
-    boolean hasGeneratedSources = false;
 
-    if (virtualImportsWithGeneratedProtoFiles) {
-      for (Artifact protoSource : protoSources) {
-        if (!protoSource.isSourceArtifact()) {
-          hasGeneratedSources = true;
-          break;
-        }
-      }
-    }
-
-    if (importPrefixAttribute == null
-        && stripImportPrefixAttribute == null
-        && protoSourceRootAttribute == null
-        && !hasGeneratedSources) {
+    if (importPrefixAttribute == null && stripImportPrefixAttribute == null) {
       // Simple case, no magic required.
       return null;
     }
 
-    if (protoSourceRootAttribute != null
-        && (importPrefixAttribute != null || stripImportPrefixAttribute != null)) {
+    if (!ruleContext.attributes().get("proto_source_root", STRING).isEmpty()) {
       ruleContext.ruleError(
           "the 'proto_source_root' attribute is incompatible with "
               + "'strip_import_prefix' and 'import_prefix");
@@ -273,62 +262,30 @@
     }
 
     PathFragment stripImportPrefix;
+    if (stripImportPrefixAttribute == null) {
+      stripImportPrefix = PathFragment.create(ruleContext.getLabel().getWorkspaceRoot());
+    } else if (stripImportPrefixAttribute.isAbsolute()) {
+      stripImportPrefix =
+          ruleContext
+              .getLabel()
+              .getPackageIdentifier()
+              .getRepository()
+              .getSourceRoot()
+              .getRelative(stripImportPrefixAttribute.toRelative());
+    } else {
+      stripImportPrefix = ruleContext.getPackageDirectory().getRelative(stripImportPrefixAttribute);
+    }
+
     PathFragment importPrefix;
-
-    if (stripImportPrefixAttribute != null || importPrefixAttribute != null) {
-      if (stripImportPrefixAttribute == null) {
-        stripImportPrefix = PathFragment.create(ruleContext.getLabel().getWorkspaceRoot());
-      } else if (stripImportPrefixAttribute.isAbsolute()) {
-        stripImportPrefix =
-            ruleContext
-                .getLabel()
-                .getPackageIdentifier()
-                .getRepository()
-                .getSourceRoot()
-                .getRelative(stripImportPrefixAttribute.toRelative());
-      } else {
-        stripImportPrefix =
-            ruleContext.getPackageDirectory().getRelative(stripImportPrefixAttribute);
-      }
-
-      if (importPrefixAttribute != null) {
-        importPrefix = importPrefixAttribute;
-      } else {
-        importPrefix = PathFragment.EMPTY_FRAGMENT;
-      }
-
-      if (importPrefix.isAbsolute()) {
-        ruleContext.attributeError("import_prefix", "should be a relative path");
-        return null;
-      }
-    } else if (protoSourceRootAttribute != null) {
-      if (!ruleContext.getFragment(ProtoConfiguration.class).enableProtoSourceroot()) {
-        ruleContext.attributeError("proto_source_root", "this attribute is not supported anymore");
-        return null;
-      }
-
-      if (!ruleContext.getLabel().getPackageFragment().equals(protoSourceRootAttribute)) {
-        ruleContext.attributeError(
-            "proto_source_root",
-            "proto_source_root must be the same as the package name ("
-                + ruleContext.getLabel().getPackageName()
-                + ")."
-                + " not '"
-                + protoSourceRootAttribute
-                + "'.");
-
-        return null;
-      }
-
-      stripImportPrefix = ruleContext.getPackageDirectory();
+    if (importPrefixAttribute == null) {
       importPrefix = PathFragment.EMPTY_FRAGMENT;
     } else {
-      // Has generated sources, but neither strip_import_prefix nor import_prefix nor
-      // proto_source_root.
-      stripImportPrefix =
-          ruleContext.getLabel().getPackageIdentifier().getRepository().getPathUnderExecRoot();
+      importPrefix = importPrefixAttribute;
+    }
 
-      importPrefix = PathFragment.EMPTY_FRAGMENT;
+    if (importPrefix.isAbsolute()) {
+      ruleContext.attributeError("import_prefix", "should be a relative path");
+      return null;
     }
 
     ImmutableList.Builder<Artifact> symlinks = ImmutableList.builder();
@@ -351,9 +308,7 @@
       symlinks.add(importsPair.second);
 
       if (!ruleContext.getFragment(ProtoConfiguration.class).doNotUseBuggyImportPath()
-          && stripImportPrefixAttribute == null
-          && protoSourceRootAttribute == null
-          && !hasGeneratedSources) {
+          && stripImportPrefixAttribute == null) {
         Pair<PathFragment, Artifact> oldImportsPair =
             computeImports(
                 ruleContext,
@@ -440,6 +395,29 @@
     return getProtoSourceRootsOfAttribute(ruleContext, currentProtoSourceRoot, "exports");
   }
 
+  private static String computeEffectiveProtoSourceRoot(RuleContext ruleContext) {
+    if (!ruleContext.attributes().isAttributeValueExplicitlySpecified("proto_source_root")) {
+      return "";
+    }
+
+    if (!ruleContext.getFragment(ProtoConfiguration.class).enableProtoSourceroot()) {
+      ruleContext.attributeError("proto_source_root", "this attribute is not supported anymore");
+      return "";
+    }
+
+    String protoSourceRoot = ruleContext.attributes().get("proto_source_root", STRING);
+    if (!ruleContext.getLabel().getPackageName().equals(protoSourceRoot)) {
+      ruleContext.attributeError(
+          "proto_source_root",
+          "proto_source_root must be the same as the package name ("
+              + ruleContext.getLabel().getPackageName() + ")."
+              + " not '" + protoSourceRoot + "'."
+      );
+    }
+
+    return protoSourceRoot;
+  }
+
   /**
    * Check that .proto files in sources are from the same package. This is done to avoid clashes
    * with the generated sources.
@@ -464,20 +442,21 @@
    * Creates the {@link ProtoInfo} for the {@code proto_library} rule associated with {@code
    * ruleContext}.
    */
-  public static ProtoInfo createProtoInfo(
-      RuleContext ruleContext, boolean virtualImportsWithGeneratedProtoFiles) {
+  public static ProtoInfo createProtoInfo(RuleContext ruleContext) {
     checkSourceFilesAreInSamePackage(ruleContext);
     ImmutableList<Artifact> directProtoSources =
         ruleContext.getPrerequisiteArtifacts("srcs", Mode.TARGET).list();
-    Library library =
-        createLibraryWithVirtualSourceRootMaybe(
-            ruleContext, directProtoSources, virtualImportsWithGeneratedProtoFiles);
+    Library library = createVirtualImportDirectoryMaybe(ruleContext, directProtoSources);
     if (ruleContext.hasErrors()) {
       return null;
     }
 
     if (library == null) {
-      library = createLibraryWithoutVirtualSourceRoot(ruleContext, directProtoSources);
+      library = getProtoSourceRoot(ruleContext, directProtoSources);
+    }
+
+    if (ruleContext.hasErrors()) {
+      return null;
     }
 
     NestedSet<Artifact> transitiveProtoSources =
diff --git a/src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoInfoStarlarkTest.java b/src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoInfoStarlarkTest.java
index 0815636..2f22ae2 100644
--- a/src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoInfoStarlarkTest.java
+++ b/src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoInfoStarlarkTest.java
@@ -164,7 +164,7 @@
   public void testProtoSourceRootExportedInStarlark() throws Exception {
 
     scratch.file(
-        "foo/myTestRule.bzl",
+        "foo/myTsetRule.bzl",
         "load('//myinfo:myinfo.bzl', 'MyInfo')",
         "",
         "def _my_test_rule_impl(ctx):",
@@ -180,7 +180,7 @@
     scratch.file(
         "foo/BUILD",
         "",
-        "load(':myTestRule.bzl', 'my_test_rule')",
+        "load(':myTsetRule.bzl', 'my_test_rule')",
         "my_test_rule(",
         "  name = 'myRule',",
         "  protodep = ':myProto',",
@@ -193,8 +193,7 @@
 
     ConfiguredTarget ct = getConfiguredTarget("//foo:myRule");
     String protoSourceRoot = (String) getMyInfoFromTarget(ct).getValue("fetched_proto_source_root");
-    String genfiles = getTargetConfiguration().getGenfilesFragment().toString();
 
-    assertThat(protoSourceRoot).isEqualTo(genfiles + "/foo/_virtual_imports/myProto");
+    assertThat(protoSourceRoot).isEqualTo("foo");
   }
 }
diff --git a/src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibraryTest.java b/src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibraryTest.java
index 803b514..225134e 100644
--- a/src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibraryTest.java
+++ b/src/test/java/com/google/devtools/build/lib/rules/proto/BazelProtoLibraryTest.java
@@ -261,13 +261,11 @@
     );
     ConfiguredTarget protoTarget = getConfiguredTarget("//x/foo:nodeps");
     ProtoInfo sourcesProvider = protoTarget.get(ProtoInfo.PROVIDER);
-    String genfiles = getTargetConfiguration().getGenfilesFragment().toString();
+    assertThat(sourcesProvider.getTransitiveProtoSourceRoots()).containsExactly("x/foo");
 
-    assertThat(sourcesProvider.getTransitiveProtoSourceRoots())
-        .containsExactly(genfiles + "/x/foo/_virtual_imports/nodeps");
-    assertThat(
-            getGeneratingSpawnAction(getDescriptorOutput("//x/foo:nodeps")).getRemainingArguments())
-        .contains("--proto_path=" + genfiles + "/x/foo/_virtual_imports/nodeps");
+    assertThat(getGeneratingSpawnAction(getDescriptorOutput("//x/foo:nodeps"))
+        .getRemainingArguments())
+        .contains("--proto_path=x/foo");
   }
 
   @Test
@@ -310,18 +308,11 @@
     );
     ConfiguredTarget protoTarget = getConfiguredTarget("//x/foo:withdeps");
     ProtoInfo sourcesProvider = protoTarget.get(ProtoInfo.PROVIDER);
-    String genfiles = getTargetConfiguration().getGenfilesFragment().toString();
-    assertThat(sourcesProvider.getTransitiveProtoSourceRoots())
-        .containsExactly(
-            genfiles + "/x/foo/_virtual_imports/dep",
-            genfiles + "/x/foo/_virtual_imports/withdeps");
+    assertThat(sourcesProvider.getTransitiveProtoSourceRoots()).containsExactly("x/foo");
 
-    assertThat(
-            getGeneratingSpawnAction(getDescriptorOutput("//x/foo:withdeps"))
-                .getRemainingArguments())
-        .containsAtLeast(
-            "--proto_path=" + genfiles + "/x/foo/_virtual_imports/withdeps",
-            "--proto_path=" + genfiles + "/x/foo/_virtual_imports/dep");
+    assertThat(getGeneratingSpawnAction(getDescriptorOutput("//x/foo:withdeps"))
+        .getRemainingArguments())
+        .contains("--proto_path=x/foo");
   }
 
   @Test
@@ -349,42 +340,8 @@
     );
     ConfiguredTarget protoTarget = getConfiguredTarget("//x/foo:withdeps");
     ProtoInfo sourcesProvider = protoTarget.get(ProtoInfo.PROVIDER);
-    String genfiles = getTargetConfiguration().getGenfilesFragment().toString();
     assertThat(sourcesProvider.getTransitiveProtoSourceRoots())
-        .containsExactly(
-            genfiles + "/x/foo/_virtual_imports/withdeps",
-            genfiles + "/x/bar/_virtual_imports/dep",
-            ".");
-  }
-
-  @Test
-  public void testExternalRepoWithGeneratedProto() throws Exception {
-    if (!isThisBazel()) {
-      return;
-    }
-
-    FileSystemUtils.appendIsoLatin1(
-        scratch.resolve("WORKSPACE"), "local_repository(name = 'foo', path = '/foo')");
-    invalidatePackages();
-
-    scratch.file("/foo/WORKSPACE");
-    scratch.file(
-        "/foo/x/BUILD",
-        "proto_library(name='x', srcs=['generated.proto'])",
-        "genrule(name='g', srcs=[], outs=['generated.proto'], cmd='')");
-
-    scratch.file("a/BUILD", "proto_library(name='a', srcs=['a.proto'], deps=['@foo//x:x'])");
-
-    String genfiles = getTargetConfiguration().getGenfilesFragment().toString();
-    ConfiguredTarget a = getConfiguredTarget("//a:a");
-    ProtoInfo aInfo = a.get(ProtoInfo.PROVIDER);
-    assertThat(aInfo.getTransitiveProtoSourceRoots())
-        .containsExactly(".", genfiles + "/external/foo/x/_virtual_imports/x");
-
-    ConfiguredTarget x = getConfiguredTarget("@foo//x:x");
-    ProtoInfo xInfo = x.get(ProtoInfo.PROVIDER);
-    assertThat(xInfo.getTransitiveProtoSourceRoots())
-        .containsExactly(genfiles + "/external/foo/x/_virtual_imports/x");
+        .containsExactly("x/foo", "x/bar", ".");
   }
 
   @Test
@@ -423,9 +380,7 @@
     // exported proto source roots should be the source root of the rule and the direct source roots
     // of its exports and nothing else (not the exports of its exports or the deps of its exports
     // or the exports of its deps)
-    String genfiles = getTargetConfiguration().getGenfilesFragment().toString();
-    assertThat(c.get(ProtoInfo.PROVIDER).getExportedProtoSourceRoots())
-        .containsExactly(genfiles + "/a/_virtual_imports/a", genfiles + "/c/_virtual_imports/c");
+    assertThat(c.get(ProtoInfo.PROVIDER).getExportedProtoSourceRoots()).containsExactly("a", "c");
   }
 
   @Test
@@ -441,10 +396,7 @@
     ConfiguredTarget protoTarget = getConfiguredTarget("//x/foo:banana");
     ProtoInfo sourcesProvider = protoTarget.get(ProtoInfo.PROVIDER);
 
-    String genfiles = getTargetConfiguration().getGenfilesFragment().toString();
-
-    assertThat(sourcesProvider.getDirectProtoSourceRoot())
-        .isEqualTo(genfiles + "/x/foo/_virtual_imports/banana");
+    assertThat(sourcesProvider.getDirectProtoSourceRoot()).isEqualTo("x/foo");
   }
 
   @Test
diff --git a/src/test/shell/bazel/bazel_proto_library_test.sh b/src/test/shell/bazel/bazel_proto_library_test.sh
index 9075736..f211683 100755
--- a/src/test/shell/bazel/bazel_proto_library_test.sh
+++ b/src/test/shell/bazel/bazel_proto_library_test.sh
@@ -121,7 +121,6 @@
 $proto_library_name(
   name = "phonenumber_proto",
   srcs = ["phonenumber/phonenumber.proto"],
-  $proto_source_root
 )
 EOF
 
@@ -382,7 +381,7 @@
 function test_proto_source_root() {
   write_workspace ""
   write_setup "proto_library" "proto_source_root = 'x/person'" ""
-  bazel build --verbose_failures //x/person:person_proto > "$TEST_log" || fail "Expected success"
+  bazel build //x/person:person_proto > "$TEST_log" || fail "Expected success"
 }
 
 function test_proto_source_root_fails() {
@@ -416,6 +415,13 @@
   bazel build //proto_library/src:all >& "$TEST_log" || fail "Expected success"
 }
 
+function test_proto_source_root_glob() {
+  write_workspace ""
+  write_regression_setup
+  bazel build //proto_library/src:all --strict_proto_deps=off >& "$TEST_log" \
+      || fail "Expected success"
+}
+
 function test_proto_source_root_multiple_workspaces() {
   write_workspace "a/b/"
   write_workspace "c/d/"