diff --git a/src/de/inetsoftware/jwebassembly/module/WasmCodeBuilder.java b/src/de/inetsoftware/jwebassembly/module/WasmCodeBuilder.java
index a7139c4..b24008a 100644
--- a/src/de/inetsoftware/jwebassembly/module/WasmCodeBuilder.java
+++ b/src/de/inetsoftware/jwebassembly/module/WasmCodeBuilder.java
@@ -374,24 +374,35 @@ public abstract class WasmCodeBuilder {
         instr = dup2 && type != ValueType.i64 && type != ValueType.f64 ? //
                         findInstructionThatPushValue( 2, javaCodePos ) : null;
 
+        int slot2;
+        if( instr != null ) {
+            slot2 = getPossibleSlot( instr );
+            if( slot2 < 0 ) {
+                slot2 = getTempVariable( instr.getPushValueType(), javaCodePos, javaCodePos + 1 );
+                if( slot < 0 ) {
+                    slot = getTempVariable( type, javaCodePos, javaCodePos + 1 );
+                    instructions.add( new WasmLoadStoreInstruction( VariableOperator.set, slot, localVariables, javaCodePos, lineNumber ) );
+                } else {
+                    instructions.add( new WasmBlockInstruction( WasmBlockOperator.DROP, null, javaCodePos, lineNumber ) );
+                }
+                instructions.add( new WasmLoadStoreInstruction( VariableOperator.tee, slot2, localVariables, javaCodePos, lineNumber ) );
+                instructions.add( new WasmLoadStoreInstruction( VariableOperator.get, slot, localVariables, javaCodePos, lineNumber ) );
+            }
+        } else {
+            slot2 = -1; // for compiler only
+        }
+
         //alternate we need to create a new locale variable
         if( slot < 0 ) {
-            if( instr != null ) {
-                throw new WasmException( "DUP2 for two slots without variables", lineNumber );
-            }
             slot = getTempVariable( type, javaCodePos, javaCodePos + 1 );
             instructions.add( new WasmLoadStoreInstruction( VariableOperator.tee, slot, localVariables, javaCodePos, lineNumber ) );
-            instructions.add( new WasmLoadStoreInstruction( VariableOperator.get, slot, localVariables, javaCodePos, lineNumber ) );
-            // an alternative solution can be a function call with multiple return values but this seems to be slower
-            // new SyntheticFunctionName( "dup" + storeType, "local.get 0 local.get 0 return", storeType, null, storeType, storeType ), codePos, lineNumber )
         } else {
-            if( instr != null ) {
-                int slot2 = getPossibleSlot( instr );
-                instructions.add( new WasmLoadStoreInstruction( VariableOperator.get, slot2, localVariables, javaCodePos, lineNumber ) );
-            }
-            instructions.add( new WasmLoadStoreInstruction( VariableOperator.get, slot, localVariables, javaCodePos, lineNumber ) );
             localVariables.expandUse( slot, javaCodePos );
         }
+        if( instr != null ) {
+            instructions.add( new WasmLoadStoreInstruction( VariableOperator.get, slot2, localVariables, javaCodePos, lineNumber ) );
+        }
+        instructions.add( new WasmLoadStoreInstruction( VariableOperator.get, slot, localVariables, javaCodePos, lineNumber ) );
     }
 
     /**
diff --git a/test/de/inetsoftware/jwebassembly/runtime/ArrayOperations.java b/test/de/inetsoftware/jwebassembly/runtime/ArrayOperations.java
index 6ceb21d..99f8ab1 100644
--- a/test/de/inetsoftware/jwebassembly/runtime/ArrayOperations.java
+++ b/test/de/inetsoftware/jwebassembly/runtime/ArrayOperations.java
@@ -19,6 +19,7 @@ import java.lang.reflect.Array;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
+import java.util.Objects;
 import java.util.zip.CRC32;
 
 import org.junit.Assume;
@@ -64,6 +65,7 @@ public class ArrayOperations extends AbstractBaseTest {
             addParam( list, script, "copyBack2Front" );
             addParam( list, script, "copyFront2Back" );
             addParam( list, script, "dup2" );
+            addParam( list, script, "dup2FromStack" );
             addParam( list, script, "dup_x2" );
             addParam( list, script, "byteArrayClassName" );
             addParam( list, script, "shortArrayClassName" );
@@ -225,6 +227,17 @@ public class ArrayOperations extends AbstractBaseTest {
             return sum;
         }
 
+        @Export
+        static int dup2FromStack() {
+            int[] data = {1,2,3};
+            int i = 0;
+
+            // use dup2 to duplicate the array and the index from stack (not variable)
+            Objects.requireNonNull( data )[i+1] |= 13;
+
+            return data[1];
+        }
+
         @Export
         static int dup_x2() {
             Object[] data = {null,null,null};