Index: oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/MigrationOptions.java
===================================================================
--- oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/MigrationOptions.java	(revision 1769379)
+++ oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/MigrationOptions.java	(working copy)
@@ -87,6 +87,8 @@
 
     private final String dstS3;
 
+    private final Boolean srcExternalBlobs;
+
     public MigrationOptions(MigrationCliArguments args) {
         this.disableMmap = args.hasOption(OptionParserFactory.DISABLE_MMAP);
         this.copyBinaries = args.hasOption(OptionParserFactory.COPY_BINARIES);
@@ -134,6 +136,13 @@
         this.dstFds = args.getOption(OptionParserFactory.DST_FDS);
         this.dstS3 = args.getOption(OptionParserFactory.DST_S3);
         this.dstS3Config = args.getOption(OptionParserFactory.DST_S3_CONFIG);
+
+        if (args.hasOption(OptionParserFactory.SRC_EXTERNAL_BLOBS)) {
+            this.srcExternalBlobs = Boolean
+                    .valueOf(OptionParserFactory.SRC_EXTERNAL_BLOBS);
+        } else {
+            this.srcExternalBlobs = null;
+        }
     }
 
     public boolean isCopyBinaries() {
@@ -329,6 +338,10 @@
             log.info("Missing binaries won't break the migration");
         }
 
+        if (srcExternalBlobs != null) {
+            log.info("Source DataStore external blobs: {}", srcExternalBlobs);
+        }
+
         log.info("Cache size: {} MB", cacheSizeInMB);
 
     }
@@ -352,4 +365,8 @@
         return calendar;
     }
 
+    public Boolean getSrcExternalBlobs() {
+        return srcExternalBlobs;
+    }
+
 }
Index: oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/OptionParserFactory.java
===================================================================
--- oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/OptionParserFactory.java	(revision 1769379)
+++ oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/OptionParserFactory.java	(working copy)
@@ -52,6 +52,8 @@
 
     public static final String SRC_S3_CONFIG = "src-s3config";
 
+    public static final String SRC_EXTERNAL_BLOBS = "src-external-ds";
+
     public static final String DST_FDS = "datastore";
 
     public static final String DST_FBS = "fileblobstore";
@@ -112,6 +114,7 @@
         op.accepts(DST_S3_CONFIG, "Configuration file for the target S3DataStore").withRequiredArg()
                 .ofType(String.class);
         op.accepts(IGNORE_MISSING_BINARIES, "Don't break the migration if some binaries are missing");
+        op.accepts(SRC_EXTERNAL_BLOBS, "Flag specifying if the source Store has external references or not");
     }
 
     private static void addRdbOptions(OptionParser op) {
Index: oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/StoreArguments.java
===================================================================
--- oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/StoreArguments.java	(revision 1769379)
+++ oak-upgrade/src/main/java/org/apache/jackrabbit/oak/upgrade/cli/parser/StoreArguments.java	(working copy)
@@ -58,6 +58,10 @@
 
         src = descriptors.get(0);
         dst = descriptors.get(1);
+
+        if (options.getSrcExternalBlobs() != null) {
+            srcHasExternalBlobRefs = options.getSrcExternalBlobs();
+        }
     }
 
     public void logOptions() {