diff --git a/YTSubConverter.Shared/Enumerations.cs b/YTSubConverter.Shared/Enumerations.cs
index a80647c..b7edfa3 100644
--- a/YTSubConverter.Shared/Enumerations.cs
+++ b/YTSubConverter.Shared/Enumerations.cs
@@ -1,5 +1,11 @@
 namespace YTSubConverter.Shared
 {
+    public enum LineMergeType
+    {
+        MoveNew,
+        MoveExisting
+    }
+
     public enum AnchorPoint
     {
         TopLeft,
diff --git a/YTSubConverter.Shared/Formats/Ass/AssDocument.cs b/YTSubConverter.Shared/Formats/Ass/AssDocument.cs
index 76a3346..1a83d6b 100644
--- a/YTSubConverter.Shared/Formats/Ass/AssDocument.cs
+++ b/YTSubConverter.Shared/Formats/Ass/AssDocument.cs
@@ -67,6 +67,7 @@ private void Load(TextReader reader, List<AssStyleOptions> styleOptions)
 
             AssDocumentSection infoSection = fileSections["Script Info"];
             VideoDimensions = new Size(infoSection.GetItemInt("PlayResX", 384), infoSection.GetItemInt("PlayResY", 288));
+            LineMergeType = infoSection.GetItemString("Collisions") == "Reverse" ? LineMergeType.MoveExisting : LineMergeType.MoveNew;
 
             _styles = fileSections["V4+ Styles"].MapItems("Style", i => new AssStyle(i))
                                                 .ToDictionaryOverwrite(s => s.Name);
diff --git a/YTSubConverter.Shared/Formats/SubtitleDocument.cs b/YTSubConverter.Shared/Formats/SubtitleDocument.cs
index 8bd2065..51e6ff5 100644
--- a/YTSubConverter.Shared/Formats/SubtitleDocument.cs
+++ b/YTSubConverter.Shared/Formats/SubtitleDocument.cs
@@ -18,11 +18,13 @@ public abstract class SubtitleDocument
         protected SubtitleDocument()
         {
             VideoDimensions = new Size(1280, 720);
+            LineMergeType = LineMergeType.MoveNew;
         }
 
         protected SubtitleDocument(SubtitleDocument doc)
         {
             VideoDimensions = doc.VideoDimensions;
+            LineMergeType = doc.LineMergeType;
             Lines.AddRange(doc.Lines.Where(l => l.Sections.Any(s => s.Text.Length > 0)));
         }
 
@@ -32,6 +34,12 @@ public Size VideoDimensions
             protected set;
         }
 
+        public LineMergeType LineMergeType
+        {
+            get;
+            protected set;
+        }
+
         public List<Line> Lines { get; } = new List<Line>();
 
         public static bool IsExtensionSupported(string extension)
@@ -143,7 +151,7 @@ public void MergeSimultaneousLines()
                 if (firstLine.Start < secondLine.Start)
                     InsertConcatenedLine(lines, i, firstLine.Start, secondLine.Start, false, firstLine);
 
-                if (AnchorPointUtil.IsBottomAligned(firstLine.AnchorPoint))
+                if (AnchorPointUtil.IsBottomAligned(firstLine.AnchorPoint) ^ (LineMergeType == LineMergeType.MoveExisting))
                     InsertConcatenedLine(lines, i, secondLine.Start, TimeUtil.Min(firstLine.End, secondLine.End), false, secondLine, firstLine);
                 else
                     InsertConcatenedLine(lines, i, secondLine.Start, TimeUtil.Min(firstLine.End, secondLine.End), false, firstLine, secondLine);
diff --git a/YTSubConverter.Tests/Ass/Files/SimultaneousReverse.ass b/YTSubConverter.Tests/Ass/Files/SimultaneousReverse.ass
new file mode 100644
index 0000000..0b8d0a0
--- /dev/null
+++ b/YTSubConverter.Tests/Ass/Files/SimultaneousReverse.ass
@@ -0,0 +1,27 @@
+[Script Info]
+; Script generated by Aegisub 3.3.0
+; http://www.aegisub.org/
+Title: Default Aegisub file
+ScriptType: v4.00+
+WrapStyle: 0
+ScaledBorderAndShadow: yes
+PlayResX: 384
+PlayResY: 288
+YCbCr Matrix: None
+Collisions: Reverse
+
+[Aegisub Project Garbage]
+Last Style Storage: Default
+Video AR Value: 1.333333
+Video Position: 129
+
+[V4+ Styles]
+Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
+Style: Default,Roboto,15,&H00FFFFFF,&HFFFFFFFF,&H3C000000,&H00000000,0,0,0,0,100,100,0,0,3,2,0,2,10,10,10,1
+Style: Soft shadow box,Roboto,15,&H00FFFFFF,&HFF0000FF,&H3C000000,&H00828282,0,0,0,0,100,100,0,0,3,2,2,2,10,10,10,1
+
+[Events]
+Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
+Dialogue: 0,0:00:00.00,0:00:04.37,Default,,0,0,0,,Line 1
+Dialogue: 0,0:00:00.60,0:00:03.70,Default,,0,0,0,,Line 2
+Dialogue: 0,0:00:01.40,0:00:02.37,Default,,0,0,0,,Line 3
diff --git a/YTSubConverter.Tests/Ass/Files/SimultaneousReverse.ytt b/YTSubConverter.Tests/Ass/Files/SimultaneousReverse.ytt
new file mode 100644
index 0000000..c7f4c49
--- /dev/null
+++ b/YTSubConverter.Tests/Ass/Files/SimultaneousReverse.ytt
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?><timedtext format="3"><head><wp id="0" ap="7" ah="0" av="0" /><wp id="1" ap="7" ah="50" av="100" /><ws id="0" ju="2" pd="0" sd="0" /><ws id="1" ju="2" pd="0" sd="0" /><pen id="0" sz="100" fc="#000000" fo="0" bo="0" /><pen id="1" sz="0" fc="#A0AAB4" fo="0" bo="0" /><pen id="2" sz="100" fc="#FEFEFE" fo="254" bc="#000000" bo="195" /></head><body><p t="1" d="616" wp="1" ws="1"><s p="1">​</s>​<s p="2">​ ​Line 1​ ​</s><s p="1">​</s></p><p t="617" d="768" wp="1" ws="1"><s p="1">​</s>​<s p="2">​ ​Line 1​ ​</s><s p="1">​
+​</s><s p="2">​ ​Line 2​ ​</s><s p="1">​</s></p><p t="1385" d="1001" wp="1" ws="1"><s p="1">​</s>​<s p="2">​ ​Line 1​ ​</s><s p="1">​
+​</s><s p="2">​ ​Line 2​ ​</s><s p="1">​
+​</s><s p="2">​ ​Line 3​ ​</s><s p="1">​</s></p><p t="2386" d="1301" wp="1" ws="1"><s p="1">​</s>​<s p="2">​ ​Line 1​ ​</s><s p="1">​
+​</s><s p="2">​ ​Line 2​ ​</s><s p="1">​</s></p><p t="3687" d="668" wp="1" ws="1"><s p="1">​</s>​<s p="2">​ ​Line 1​ ​</s><s p="1">​</s></p></body></timedtext>
\ No newline at end of file