diff --git a/.gitignore b/.gitignore
index ef2a133..1867f0b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,3 +42,5 @@ gradlew.bat
 gradlew
 gradle.properties
 gradle/
+.DS_Store
+.DS_Store/
diff --git a/layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/blockification/DocstrumBlockificationService.java b/layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/blockification/DocstrumBlockificationService.java
index 92f3a73..c3666a6 100644
--- a/layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/blockification/DocstrumBlockificationService.java
+++ b/layoutparser-service/layoutparser-service-processor/src/main/java/com/knecon/fforesight/service/layoutparser/processor/services/blockification/DocstrumBlockificationService.java
@@ -221,9 +221,11 @@ public class DocstrumBlockificationService {
     public void mergeIntersectingBlocks(List<AbstractPageBlock> blocks, float xThreshold, float yThreshold) {
 
         ListIterator<AbstractPageBlock> itty = blocks.listIterator();
-        Set<AbstractPageBlock> toRemove = new HashSet<>();
         while (itty.hasNext()) {
             AbstractPageBlock block = itty.next();
+            if(block == null){
+                continue;
+            }
             if (block instanceof TablePageBlock) {
                 continue;
             }
@@ -232,7 +234,7 @@ public class DocstrumBlockificationService {
 
             for (int i = 0; i < blocks.size(); i++) {
 
-                if (toRemove.contains(blocks.get(i))) {
+                if(blocks.get(i) == null){
                     continue;
                 }
                 if (blocks.get(i) == current) {
@@ -249,13 +251,19 @@ public class DocstrumBlockificationService {
                     boolean toDuplicate = current.isToDuplicate() || inner.isToDuplicate();
                     current.getSequences().addAll(inner.getSequences());
                     current = buildTextBlock(current.getSequences(), 0);
+
                     current.setToDuplicate(toDuplicate);
-                    toRemove.add(inner);
+                    blocks.set(i, null);
                     itty.set(current);
                 }
             }
         }
-        blocks.removeAll(toRemove);
+        var blocksIterator = blocks.iterator();
+        while(blocksIterator.hasNext()){
+            if(blocksIterator.next() == null){
+                blocksIterator.remove();
+            }
+        }
     }