diff --git a/dev-tools/scripts/addBackcompatIndexes.py b/dev-tools/scripts/addBackcompatIndexes.py
index 1cada018c89..03e858cb505 100644
--- a/dev-tools/scripts/addBackcompatIndexes.py
+++ b/dev-tools/scripts/addBackcompatIndexes.py
@@ -121,8 +121,8 @@ def update_backcompat_tests(types, index_version, current_version):
     def __call__(self, buffer, match, line):
       if self.start:
         # find where this version should exist
-        i = len(buffer) - 1 
-        previous_version_exists = '};' not in line # Version list closure => there are no versions
+        i = len(buffer) - 1
+        previous_version_exists = not ('};' in line and buffer[-1].strip().endswith("{"))
         if previous_version_exists: # Only look if there is a version here
           v = find_version(buffer[i])
           while i >= self.start and v.on_or_after(index_version):
@@ -143,7 +143,7 @@ def update_backcompat_tests(types, index_version, current_version):
           last = buffer[-1]
           spaces = ' ' * (len(last) - len(last.lstrip()))
         else:
-          spaces = '      '
+          spaces = '    '
         for (j, t) in enumerate(types):
           if t == 'sorted':
             newline = spaces + ('"sorted.%s"') % index_version
diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java b/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
index 88900d439bc..7437e75679a 100644
--- a/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
+++ b/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
@@ -287,8 +287,8 @@ public class TestBackwardsCompatibility extends LuceneTestCase {
   }
 
   final static String[] oldNames = {
-      "7.0.0-cfs",
-      "7.0.0-nocfs"
+    "7.0.0-cfs",
+    "7.0.0-nocfs"
   };
 
   public static String[] getOldNames() {
@@ -296,7 +296,7 @@ public class TestBackwardsCompatibility extends LuceneTestCase {
   }
   
   final static String[] oldSortedNames = {
-      "sorted.7.0.0"
+    "sorted.7.0.0"
   };
 
   public static String[] getOldSortedNames() {