diff --git a/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java b/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
index 4160555..5fac4f0 100644
--- a/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
+++ b/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
@@ -442,6 +442,9 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
             case l2i:
                 op = I32_WRAP_I64;
                 break;
+            case i2l:
+                op = I64_EXTEND_S_I32;
+                break;
             default:
                 throw new Error( "Unknown cast: " + cast );
         }
diff --git a/src/de/inetsoftware/jwebassembly/binary/InstructionOpcodes.java b/src/de/inetsoftware/jwebassembly/binary/InstructionOpcodes.java
index e4fee88..c24fbb4 100644
--- a/src/de/inetsoftware/jwebassembly/binary/InstructionOpcodes.java
+++ b/src/de/inetsoftware/jwebassembly/binary/InstructionOpcodes.java
@@ -117,4 +117,5 @@ interface InstructionOpcodes {
 
     static final int I32_WRAP_I64           = 0xA7;
 
+    static final int I64_EXTEND_S_I32       = 0xAC;
 }
diff --git a/src/de/inetsoftware/jwebassembly/module/ModuleWriter.java b/src/de/inetsoftware/jwebassembly/module/ModuleWriter.java
index 4d9d671..eb79f40 100644
--- a/src/de/inetsoftware/jwebassembly/module/ModuleWriter.java
+++ b/src/de/inetsoftware/jwebassembly/module/ModuleWriter.java
@@ -399,18 +399,21 @@ public abstract class ModuleWriter implements Closeable {
                         writeNumericOperator( NumericOperator.shl, ValueType.i32 );
                         break;
                     case 121: // lshl
+                        writeCast( ValueTypeConvertion.i2l ); // the shift parameter must be of type long!!!
                         writeNumericOperator( NumericOperator.shl, ValueType.i64 );
                         break;
                     case 122: // ishr
                         writeNumericOperator( NumericOperator.shr_s, ValueType.i32 );
                         break;
                     case 123: // lshr
+                        writeCast( ValueTypeConvertion.i2l ); // the shift parameter must be of type long!!!
                         writeNumericOperator( NumericOperator.shr_s, ValueType.i64 );
                         break;
                     case 124: // iushr
                         writeNumericOperator( NumericOperator.shr_u, ValueType.i32 );
                         break;
                     case 125: // lushr
+                        writeCast( ValueTypeConvertion.i2l ); // the shift parameter must be of type long!!!
                         writeNumericOperator( NumericOperator.shr_u, ValueType.i64 );
                         break;
                     case 126: // iand
diff --git a/src/de/inetsoftware/jwebassembly/module/ValueTypeConvertion.java b/src/de/inetsoftware/jwebassembly/module/ValueTypeConvertion.java
index 2e5610a..087394b 100644
--- a/src/de/inetsoftware/jwebassembly/module/ValueTypeConvertion.java
+++ b/src/de/inetsoftware/jwebassembly/module/ValueTypeConvertion.java
@@ -23,4 +23,5 @@ package de.inetsoftware.jwebassembly.module;
  */
 public enum ValueTypeConvertion {
     l2i,
+    i2l,
 }
diff --git a/src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java b/src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java
index 56af721..2825e6d 100644
--- a/src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java
+++ b/src/de/inetsoftware/jwebassembly/text/TextModuleWriter.java
@@ -179,6 +179,9 @@ public class TextModuleWriter extends ModuleWriter {
             case l2i:
                 op = "i32.wrap/i64";
                 break;
+            case i2l:
+                op = "i64.extend_s/i32";
+                break;
             default:
                 throw new Error( "Unknown cast: " + cast );
         }
diff --git a/test/de/inetsoftware/jwebassembly/math/MathOperations.java b/test/de/inetsoftware/jwebassembly/math/MathOperations.java
index 8d06bbe..09d272f 100644
--- a/test/de/inetsoftware/jwebassembly/math/MathOperations.java
+++ b/test/de/inetsoftware/jwebassembly/math/MathOperations.java
@@ -67,6 +67,8 @@ public class MathOperations {
             addParam( list, script, "mulDivLong" );
             addParam( list, script, "mulDivFloat" );
             addParam( list, script, "mulDivDouble" );
+            addParam( list, script, "intBits" );
+            addParam( list, script, "longBits" );
         }
         return list;
     }
@@ -177,5 +179,29 @@ public class MathOperations {
             return a;
         }
 
+        @Export
+        static int intBits() {
+            int a = 1;
+            a = a << 1;
+            a = a | 15;
+            a = a & 4;
+            int b = Integer.MIN_VALUE;
+            b = b >>> 1;
+            b = b >> 2;
+            return a ^ b;
+        }
+
+        @Export
+        static int longBits() {
+            long a = 1;
+            a = a << 1;
+            a = a | 15;
+            a = a & 4;
+            long b = Long.MIN_VALUE;
+            b = b >>> 1;
+            b = b >> 2;
+            return (int)(a ^ (b >> 32));
+        }
+
     }
 }