diff --git a/README.md b/README.md
index 233222e..24bdc56 100644
--- a/README.md
+++ b/README.md
@@ -15,8 +15,8 @@ Status of the project
 * Public API of the Compiler
 
 ### Partially Finished
-* Binary format file writer (130 of 201 byte code instructions)
-* Text format file writer (130 of 201 byte code instructions)
+* Binary format file writer (134 of 201 byte code instructions)
+* Text format file writer (134 of 201 byte code instructions)
 
 ### Open Features
 * Exception handling - required the next version of WebAssembly
diff --git a/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java b/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
index c50fb0f..df3b412 100644
--- a/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
+++ b/src/de/inetsoftware/jwebassembly/binary/BinaryModuleWriter.java
@@ -336,6 +336,16 @@ public class BinaryModuleWriter extends ModuleWriter implements InstructionOpcod
                         break;
                 }
                 break;
+            case neg:
+                switch( valueType ) {
+                    case f32:
+                        op = F32_NEG;
+                        break;
+                    case f64:
+                        op = F64_NEG;
+                        break;
+                }
+                break;
             case mul:
                 switch( valueType ) {
                     case i32:
diff --git a/src/de/inetsoftware/jwebassembly/module/ModuleWriter.java b/src/de/inetsoftware/jwebassembly/module/ModuleWriter.java
index 1d1c7d5..264cc7d 100644
--- a/src/de/inetsoftware/jwebassembly/module/ModuleWriter.java
+++ b/src/de/inetsoftware/jwebassembly/module/ModuleWriter.java
@@ -548,6 +548,20 @@ public abstract class ModuleWriter implements Closeable {
                     case 115: // drem
                         //TODO can be implemented with a helper function like: (a - (long)(a / b) * (double)b) 
                         throw new WasmException( "Modulo/Remainder for floating numbers is not supported in WASM. Use int or long data types." + op, sourceFile, lineNumber );
+                    case 116: // ineg
+                        writeConstInt( -1 );
+                        writeNumericOperator( NumericOperator.mul, ValueType.i32 );
+                        break;
+                    case 117: // lneg
+                        writeConstLong( -1 );
+                        writeNumericOperator( NumericOperator.mul, ValueType.i64 );
+                        break;
+                    case 118: // fneg
+                        writeNumericOperator( NumericOperator.neg, ValueType.f32 );
+                        break;
+                    case 119: // dneg
+                        writeNumericOperator( NumericOperator.neg, ValueType.f64 );
+                        break;
                     case 120: // ishl
                         writeNumericOperator( NumericOperator.shl, ValueType.i32 );
                         break;
diff --git a/src/de/inetsoftware/jwebassembly/module/NumericOperator.java b/src/de/inetsoftware/jwebassembly/module/NumericOperator.java
index 3c61a69..ff6f7c9 100644
--- a/src/de/inetsoftware/jwebassembly/module/NumericOperator.java
+++ b/src/de/inetsoftware/jwebassembly/module/NumericOperator.java
@@ -21,6 +21,7 @@ package de.inetsoftware.jwebassembly.module;
 public enum NumericOperator {
     add,
     sub,
+    neg,
     mul,
     div,
     rem,
diff --git a/test/de/inetsoftware/jwebassembly/runtime/MathOperations.java b/test/de/inetsoftware/jwebassembly/runtime/MathOperations.java
index 94e23e7..da2617f 100644
--- a/test/de/inetsoftware/jwebassembly/runtime/MathOperations.java
+++ b/test/de/inetsoftware/jwebassembly/runtime/MathOperations.java
@@ -90,6 +90,7 @@ public class MathOperations extends AbstractBaseTest {
         static int addInt( int a, int b ) {
             int c = 1234567;
             int e = -1;
+            e = -e;
             double d = -1234567;
             int i = 1;
             long l = 2;
@@ -101,7 +102,8 @@ public class MathOperations extends AbstractBaseTest {
         @Export
         static int addLong() {
             long a = 1L;
-            long b = 3L;
+            long b = -3L;
+            b = -b;
             return (int)(a + b);
         }
 
@@ -110,6 +112,7 @@ public class MathOperations extends AbstractBaseTest {
             float c = -1;
             float e = 1.25F;
             double d = 1234;
+            e = -e;
             int i = 1;
             long l = 2;
             float f = 3;
@@ -121,6 +124,7 @@ public class MathOperations extends AbstractBaseTest {
             double c = -1;
             double d = 1234;
             double e = 1.25;
+            e = -e;
             int i = 1;
             long l = 2;
             float f = 3;