diff --git a/CHANGELOG.md b/CHANGELOG.md
index c02db382f..5660ce5eb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@ All notable changes to this project will be documented in this file.
 ## [Unreleased]
 ### Fixed
 - Japanese in english locales for Gotoaddress, addclass dialog
+- AS1/2 DefineFunction cleaner
 
 ## [14.5.2] - 2021-11-20
 ### Fixed
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/action/ActionDefineFunctionPushRegistersCleaner.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/action/ActionDefineFunctionPushRegistersCleaner.java
index 72c2bdd46..8ecb32dde 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/action/ActionDefineFunctionPushRegistersCleaner.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/action/ActionDefineFunctionPushRegistersCleaner.java
@@ -12,7 +12,8 @@
  * Lesser General Public License for more details.
  * 
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library.
 */
+ * License along with this library.
+ */
 package com.jpexs.decompiler.flash.action;
 
 import com.jpexs.decompiler.flash.SWF;
@@ -206,7 +207,25 @@ public class ActionDefineFunctionPushRegistersCleaner extends SWFDecompilerAdapt
                 return false;
             }
 
-            Iterator<Action> ait = code.getReferencesFor(asr);
+            Action actionWithRefs = asr;
+
+            //Special: ignore zero jump when pushundefined is stripped as unreachable            
+            if (code.get(pos - 1) instanceof ActionJump) {
+                if (((ActionJump) code.get(pos - 1)).getJumpOffset() == 0) {
+                    Iterator<Action> zit = code.getReferencesFor(code.get(pos));
+                    int refCnt = 0;
+                    while (zit.hasNext()) {
+                        zit.next();
+                        refCnt++;
+                    }
+                    if (refCnt == 1) {
+                        actionWithRefs = code.get(pos - 1);
+                        pos--;
+                    }
+                }
+            }
+
+            Iterator<Action> ait = code.getReferencesFor(actionWithRefs);
             while (ait.hasNext()) {
                 Action a = ait.next();
                 if (!(a instanceof ActionJump)) {
@@ -215,6 +234,7 @@ public class ActionDefineFunctionPushRegistersCleaner extends SWFDecompilerAdapt
                 jumpsToReturnPositions.add(code.indexOf(a));
             }
             pos--;
+
             if (!(code.get(pos) instanceof ActionJump)) {
                 actionBeforeFinishPart = code.get(pos);
             }
diff --git a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/action/ActionListReader.java b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/action/ActionListReader.java
index 6f7c134b4..c3757582a 100644
--- a/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/action/ActionListReader.java
+++ b/libsrc/ffdec_lib/src/com/jpexs/decompiler/flash/action/ActionListReader.java
@@ -12,7 +12,8 @@
  * Lesser General Public License for more details.
  * 
  * You should have received a copy of the GNU Lesser General Public
- * License along with this library.
 */
+ * License along with this library.
+ */
 package com.jpexs.decompiler.flash.action;
 
 import com.jpexs.decompiler.flash.DisassemblyListener;
@@ -28,13 +29,16 @@ import com.jpexs.decompiler.flash.action.swf4.ActionJump;
 import com.jpexs.decompiler.flash.action.swf4.ActionPush;
 import com.jpexs.decompiler.flash.action.swf5.ActionConstantPool;
 import com.jpexs.decompiler.flash.configuration.Configuration;
+import com.jpexs.decompiler.flash.exporters.modes.ScriptExportMode;
 import com.jpexs.decompiler.flash.helpers.SWFDecompilerPlugin;
 import com.jpexs.decompiler.graph.GraphSourceItemContainer;
 import com.jpexs.helpers.CancellableWorker;
+import com.jpexs.helpers.Helper;
 import com.jpexs.helpers.stat.Statistics;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -163,6 +167,13 @@ public class ActionListReader {
             }
         }
 
+        /*System.err.println("=======================");
+        int p = 0;
+        for (Action a : actions) {
+            System.err.println("loc" + Helper.formatAddress(a.getAddress()) + " (" + p + "): " + a.getASMSource(actions, new HashSet<Long>(), ScriptExportMode.PCODE));
+            p++;
+        }*/
+
         //TODO: This cleaner needs to be executed only before actual decompilation, not when disassembly only
         try {
             new ActionDefineFunctionPushRegistersCleaner().actionListParsed(actions, sis.getSwf());
diff --git a/libsrc/ffdec_lib/test/com/jpexs/decompiler/flash/ActionScript2AssemblerTest.java b/libsrc/ffdec_lib/test/com/jpexs/decompiler/flash/ActionScript2AssemblerTest.java
index 30f6f7dff..d6cb83b02 100644
--- a/libsrc/ffdec_lib/test/com/jpexs/decompiler/flash/ActionScript2AssemblerTest.java
+++ b/libsrc/ffdec_lib/test/com/jpexs/decompiler/flash/ActionScript2AssemblerTest.java
@@ -147,4 +147,49 @@ public class ActionScript2AssemblerTest extends ActionScript2TestBase {
                 + "}\n"
                 + "}");
     }
+
+    @Test
+    public void testDefineFuncRegCleaner() {
+        String res = decompilePcode("ConstantPool \"Math\" \"randi\" \"random\" \"b\" \"a\" \"floor\" \"randf\" \"randa\" \"arguments\" \"rande\" \"sign\" \"abs\"\n"
+                + "Push constant0\n"
+                + "GetVariable\n"
+                + "Push constant10\n"
+                + "definefunction \"\" 1 \"a\" { \n"
+                + "push register1 constant4\n"
+                + "getvariable\n"
+                + "storeregister 1\n"
+                + "pop\n"
+                + "push register1 0.0\n"
+                + "Equals2\n"
+                + "If locC\n"
+                + "push register1 1 constant0\n"
+                + "getvariable\n"
+                + "push constant11\n"
+                + "callmethod\n"
+                + "push register1\n"
+                + "divide\n"
+                + "jump locB\n"
+                + "locC:\n"
+                + "push 0.0\n"
+                + "locB: jump locA\n"
+                + "push undefined\n"
+                + "locA: storeregister 0\n"
+                + "pop\n"
+                + "storeregister 1\n"
+                + "pop\n"
+                + "push register0\n"
+                + "return\n"
+                + "}\n"
+                + "loc00a5:SetMember");
+        res = cleanPCode(res);
+        assertEquals(res, "Math.sign = function(a)\n"
+                + "{\n"
+                + "var _loc1_ = a;\n"
+                + "if(_loc1_ != 0)\n"
+                + "{\n"
+                + "return Math.abs(_loc1_) / _loc1_;\n"
+                + "}\n"
+                + "return 0;\n"
+                + "};");
+    }
 }