diff --git a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
index 5c276b4..b14b049 100644
--- a/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
+++ b/fs_mgr/libsnapshot/include/libsnapshot/snapshot.h
@@ -452,6 +452,7 @@
 
     std::string GetSnapshotBootIndicatorPath();
     std::string GetRollbackIndicatorPath();
+    std::string GetForwardMergeIndicatorPath();
 
     // Return the name of the device holding the "snapshot" or "snapshot-merge"
     // target. This may not be the final device presented via MapSnapshot(), if
diff --git a/fs_mgr/libsnapshot/snapshot.cpp b/fs_mgr/libsnapshot/snapshot.cpp
index b825805..6c18b17 100644
--- a/fs_mgr/libsnapshot/snapshot.cpp
+++ b/fs_mgr/libsnapshot/snapshot.cpp
@@ -228,10 +228,17 @@
         return false;
     }
 
-    // It's okay if these fail - first-stage init performs a deeper check after
+    // It's okay if these fail:
+    // - For SnapshotBoot and Rollback, first-stage init performs a deeper check after
     // reading the indicator file, so it's not a problem if it still exists
     // after the update completes.
-    std::vector<std::string> files = {GetSnapshotBootIndicatorPath(), GetRollbackIndicatorPath()};
+    // - For ForwardMerge, FinishedSnapshotWrites asserts that the existence of the indicator
+    // matches the incoming update.
+    std::vector<std::string> files = {
+            GetSnapshotBootIndicatorPath(),
+            GetRollbackIndicatorPath(),
+            GetForwardMergeIndicatorPath(),
+    };
     for (const auto& file : files) {
         RemoveFileIfExists(file);
     }
@@ -992,6 +999,10 @@
     return metadata_dir_ + "/" + android::base::Basename(kRollbackIndicatorPath);
 }
 
+std::string SnapshotManager::GetForwardMergeIndicatorPath() {
+    return metadata_dir_ + "/allow-forward-merge";
+}
+
 void SnapshotManager::AcknowledgeMergeSuccess(LockedFile* lock) {
     RemoveAllUpdateState(lock);
 }
@@ -2438,6 +2449,9 @@
     ss << "Rollback indicator: "
        << (access(GetRollbackIndicatorPath().c_str(), F_OK) == 0 ? "exists" : strerror(errno))
        << std::endl;
+    ss << "Forward merge indicator: "
+       << (access(GetForwardMergeIndicatorPath().c_str(), F_OK) == 0 ? "exists" : strerror(errno))
+       << std::endl;
 
     bool ok = true;
     std::vector<std::string> snapshots;