diff --git a/base/src/com/google/idea/blaze/base/command/info/BlazeInfo.java b/base/src/com/google/idea/blaze/base/command/info/BlazeInfo.java
index 05bd9f7f942..27b3be9c5e7 100644
--- a/base/src/com/google/idea/blaze/base/command/info/BlazeInfo.java
+++ b/base/src/com/google/idea/blaze/base/command/info/BlazeInfo.java
@@ -36,6 +36,8 @@ public abstract class BlazeInfo implements ProtoWrapper<ProjectData.BlazeInfo> {
   public static final String MASTER_LOG = "master-log";
   public static final String RELEASE = "release";
 
+  public static final String STARLARK_SEMANTICS = "starlark-semantics";
+
   public static String blazeBinKey(BuildSystemName buildSystemName) {
     switch (buildSystemName) {
       case Blaze:
diff --git a/base/src/com/google/idea/blaze/base/command/info/BlazeInfoRunnerImpl.java b/base/src/com/google/idea/blaze/base/command/info/BlazeInfoRunnerImpl.java
index 4c792c6ce81..682e2fd45c5 100644
--- a/base/src/com/google/idea/blaze/base/command/info/BlazeInfoRunnerImpl.java
+++ b/base/src/com/google/idea/blaze/base/command/info/BlazeInfoRunnerImpl.java
@@ -18,6 +18,7 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.idea.blaze.base.async.executor.BlazeExecutor;
 import com.google.idea.blaze.base.bazel.BuildSystem.BuildInvoker;
 import com.google.idea.blaze.base.command.BlazeCommand;
@@ -26,6 +27,7 @@
 import com.google.idea.blaze.base.scope.BlazeContext;
 import com.google.idea.blaze.base.settings.BuildSystemName;
 import com.intellij.openapi.project.Project;
+
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.util.List;
@@ -76,16 +78,27 @@ public ListenableFuture<BlazeInfo> runBlazeInfo(
       BlazeContext context,
       BuildSystemName buildSystemName,
       List<String> blazeFlags) {
-    return Futures.transform(
+    ListeningExecutorService executor = BlazeExecutor.getInstance().getExecutor();
+
+    return Futures.transformAsync(
         runBlazeInfoGetBytes(project, invoker, context, blazeFlags, /* key= */ null),
-        bytes ->
-            BlazeInfo.create(
-                buildSystemName,
-                parseBlazeInfoResult(new String(bytes, StandardCharsets.UTF_8).trim())),
-        BlazeExecutor.getInstance().getExecutor());
+        bytes -> {
+          ImmutableMap.Builder<String, String> builder = parseBlazeInfoResult(new String(bytes, StandardCharsets.UTF_8).trim());
+
+          return Futures.transform(
+              runBlazeInfo(project, invoker, context, blazeFlags, BlazeInfo.STARLARK_SEMANTICS),
+
+              starLarkSemantics -> {
+                builder.put(BlazeInfo.STARLARK_SEMANTICS, starLarkSemantics);
+
+                return BlazeInfo.create(buildSystemName, builder.build());
+              }, executor);
+        },
+        executor);
   }
-  private static ImmutableMap<String, String> parseBlazeInfoResult(String blazeInfoString) {
-    ImmutableMap.Builder<String, String> blazeInfoMapBuilder = ImmutableMap.builder();
+
+  private static ImmutableMap.Builder<String, String> parseBlazeInfoResult(String blazeInfoString) {
+    ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
     String[] blazeInfoLines = blazeInfoString.split("\n");
     for (String blazeInfoLine : blazeInfoLines) {
       // Just split on the first ":".
@@ -96,8 +109,9 @@ private static ImmutableMap<String, String> parseBlazeInfoResult(String blazeInf
       }
       String key = keyValue[0].trim();
       String value = keyValue[1].trim();
-      blazeInfoMapBuilder.put(key, value);
+      builder.put(key, value);
     }
-    return blazeInfoMapBuilder.build();
+
+    return builder;
   }
 }
diff --git a/base/src/com/google/idea/blaze/base/model/ExternalWorkspaceDataProvider.java b/base/src/com/google/idea/blaze/base/model/ExternalWorkspaceDataProvider.java
index 039953c105d..98f4f03c3fe 100644
--- a/base/src/com/google/idea/blaze/base/model/ExternalWorkspaceDataProvider.java
+++ b/base/src/com/google/idea/blaze/base/model/ExternalWorkspaceDataProvider.java
@@ -20,6 +20,7 @@
 import com.google.idea.blaze.base.async.executor.BlazeExecutor;
 import com.google.idea.blaze.base.bazel.BazelVersion;
 import com.google.idea.blaze.base.bazel.BuildSystem;
+import com.google.idea.blaze.base.command.info.BlazeInfo;
 import com.google.idea.blaze.base.command.mod.BlazeModException;
 import com.google.idea.blaze.base.command.mod.BlazeModRunner;
 import com.google.idea.blaze.base.scope.BlazeContext;
@@ -67,11 +68,21 @@ static Boolean isEnabled(BlazeVersionData blazeVersionData) {
   public ListenableFuture<ExternalWorkspaceData> getExternalWorkspaceData(
       BlazeContext context,
       List<String> blazeFlags,
-      BlazeVersionData blazeVersionData) {
+      BlazeVersionData blazeVersionData,
+      BlazeInfo blazeInfo
+  ) {
+    // check minimum bazel version
     if (!isEnabled(blazeVersionData)) {
       return Futures.immediateFuture(ExternalWorkspaceData.EMPTY);
     }
 
+    // validate that bzlmod is enabled (technically this validates that the --enable_bzlmod is not
+    // changed from the default `true` aka set to false)
+    String starLarkSemantics = blazeInfo.get(BlazeInfo.STARLARK_SEMANTICS);
+    if (starLarkSemantics == null || starLarkSemantics.isEmpty() || starLarkSemantics.contains("enable_bzlmod=false")) {
+      return Futures.immediateFuture(ExternalWorkspaceData.EMPTY);
+    }
+
     return BlazeExecutor.getInstance().submit(() -> {
       ExternalWorkspaceData mapping = getCachedExternalWorkspaceData(context, blazeFlags);
       if (mapping == null) {
@@ -114,6 +125,7 @@ public ListenableFuture<ExternalWorkspaceData> getExternalWorkspaceData(
   }
 
   public void invalidate(BlazeContext context, SyncMode syncMode) {
+    logger.info("Invalidating External Repository Mapping info");
     context.output(new StatusOutput(String.format("Invalidating External Repository Mapping info (%s)", syncMode)));
     externalWorkspaceData = null;
   }
@@ -124,7 +136,7 @@ public void onSyncStart(
         Project project,
         BlazeContext context,
         SyncMode syncMode) {
-      if (syncMode == SyncMode.NO_BUILD || syncMode == SyncMode.FULL) {
+      if (syncMode == SyncMode.FULL) {
         ExternalWorkspaceDataProvider provider = ExternalWorkspaceDataProvider.getInstance(project);
         if (provider != null) {
           provider.invalidate(context, syncMode);
diff --git a/base/src/com/google/idea/blaze/base/sync/ProjectStateSyncTask.java b/base/src/com/google/idea/blaze/base/sync/ProjectStateSyncTask.java
index cc49b7f8f2a..8bbdcb1a480 100644
--- a/base/src/com/google/idea/blaze/base/sync/ProjectStateSyncTask.java
+++ b/base/src/com/google/idea/blaze/base/sync/ProjectStateSyncTask.java
@@ -161,7 +161,7 @@ private SyncProjectState getProjectState(BlazeContext context, BlazeSyncParams p
     }
 
     ExternalWorkspaceData externalWorkspaceData =
-        getExternalWorkspaceData(context, projectViewSet, blazeVersionData, params.syncMode());
+        getExternalWorkspaceData(context, projectViewSet, blazeVersionData, blazeInfo, params.syncMode());
 
     WorkspacePathResolver workspacePathResolver =
         workspacePathResolverAndProjectView.workspacePathResolver;
@@ -229,6 +229,7 @@ private ExternalWorkspaceData getExternalWorkspaceData(
       BlazeContext context,
       ProjectViewSet projectViewSet,
       BlazeVersionData blazeVersionData,
+      BlazeInfo blazeInfo,
       SyncMode syncMode)
       throws SyncCanceledException, SyncFailedException {
 
@@ -242,7 +243,7 @@ private ExternalWorkspaceData getExternalWorkspaceData(
 
     ListenableFuture<ExternalWorkspaceData> externalWorkspaceDataFuture =
         ExternalWorkspaceDataProvider.getInstance(project)
-            .getExternalWorkspaceData(context, syncFlags, blazeVersionData);
+            .getExternalWorkspaceData(context, syncFlags, blazeVersionData, blazeInfo);
 
     FutureResult<ExternalWorkspaceData> externalWorkspaceDataResult =
         FutureUtil.waitForFuture(context, externalWorkspaceDataFuture)