diff --git a/platform/lang-impl/src/com/intellij/util/indexing/unindexedFilesScannerStartup.kt b/platform/lang-impl/src/com/intellij/util/indexing/unindexedFilesScannerStartup.kt
index 6b3046e591ca..eb2c6d96e98c 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/unindexedFilesScannerStartup.kt
+++ b/platform/lang-impl/src/com/intellij/util/indexing/unindexedFilesScannerStartup.kt
@@ -6,6 +6,7 @@ import com.intellij.openapi.application.readAction
 import com.intellij.openapi.application.readActionBlocking
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.Key
+import com.intellij.openapi.util.ThrowableComputable
 import com.intellij.openapi.util.registry.Registry
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.openapi.vfs.VirtualFileWithId
@@ -145,11 +146,15 @@ private fun scheduleFullScanning(
   }
   else CompletableDeferred(Unit)
   val parameters = CompletableDeferred(ScanningIterators(indexingReason, null, null, fullScanningType))
-  UnindexedFilesScanner(project, true, isFilterUpToDate,
-                        someDirtyFilesScheduledForIndexing.asCompletableFuture(),
-                        forceCheckingForOutdatedIndexesUsingFileModCount = notSeenIds !is AllNotSeenDirtyFileIds,
-                        scanningParameters = parameters)
-    .queue()
+  ApplicationManager.getApplication().invokeAndWait {
+    ApplicationManager.getApplication().runWriteIntentReadAction(ThrowableComputable { // makes scanning to be scheduled immediately
+      UnindexedFilesScanner(project, true, isFilterUpToDate,
+                            someDirtyFilesScheduledForIndexing.asCompletableFuture(),
+                            forceCheckingForOutdatedIndexesUsingFileModCount = notSeenIds !is AllNotSeenDirtyFileIds,
+                            scanningParameters = parameters)
+        .queue()
+    })
+  }
   return someDirtyFilesScheduledForIndexing
 }
 
@@ -173,10 +178,14 @@ private fun scheduleDirtyFilesScanning(
                          DirtyFilesIndexableFilesIterator(projectDirtyFilesFromOrphanQueue, true))
 
   val scanningIterators = CompletableDeferred(ScanningIterators(indexingReason, iterators, null, partialScanningType))
-  UnindexedFilesScanner(project, true, true,
-                        projectDirtyFiles.asCompletableFuture(),
-                        scanningParameters = scanningIterators)
-    .queue()
+  ApplicationManager.getApplication().invokeAndWait {
+    ApplicationManager.getApplication().runWriteIntentReadAction(ThrowableComputable { // makes scanning to be scheduled immediately
+      UnindexedFilesScanner(project, true, true,
+                            projectDirtyFiles.asCompletableFuture(),
+                            scanningParameters = scanningIterators)
+        .queue()
+    })
+  }
   return projectDirtyFiles
 }