diff --git a/src/libse/Common/MergeLinesSameTextUtils.cs b/src/libse/Common/MergeLinesSameTextUtils.cs
index a84c1545f..24e060406 100644
--- a/src/libse/Common/MergeLinesSameTextUtils.cs
+++ b/src/libse/Common/MergeLinesSameTextUtils.cs
@@ -50,6 +50,10 @@ namespace Nikse.SubtitleEdit.Core.Common
                             mergedIndexes.Add(i - 1);
                         }
                     }
+                    else
+                    {
+                        break;
+                    }
                 }
             }
 
diff --git a/src/ui/Forms/MergeDoubleLines.cs b/src/ui/Forms/MergeDoubleLines.cs
index bbeadd584..e4501a680 100644
--- a/src/ui/Forms/MergeDoubleLines.cs
+++ b/src/ui/Forms/MergeDoubleLines.cs
@@ -195,6 +195,10 @@ namespace Nikse.SubtitleEdit.Forms
                             mergedIndexes.Add(i - 1);
                         }
                     }
+                    else
+                    {
+                        break;
+                    }
                 }
 
                 if (!removed.Contains(i - 1) && lineNumbers.Count > 0 && clearFixes)