2 files changed, 5 insertions, 5 deletions
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java b/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
index 22167a87..1f562378 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/node/DivNode.java
@@ -23,11 +23,10 @@ public class DivNode extends Node {
     public Type compute() {
         if (in(1)._type instanceof TypeInteger i0 &&
             in(2)._type instanceof TypeInteger i1) {
-            if (i0.isConstant() && i1.isConstant()) {
-                if (i1.value() == 0)
-                    throw new IllegalArgumentException("Divide by zero");
-                return TypeInteger.constant(i0.value()/i1.value());
-            }
+            if (i0.isConstant() && i1.isConstant())
+                return i1.value() == 0
+                    ? TypeInteger.ZERO
+                    : TypeInteger.constant(i0.value()/i1.value());
             return i0.meet(i1);
         }
         return TypeBot.BOTTOM;
diff --git a/chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java b/chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java
index e23840e0..b53b1b29 100644
--- a/chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java
+++ b/chapter04/src/main/java/com/seaofnodes/simple/type/TypeInteger.java
@@ -7,6 +7,7 @@ public class TypeInteger extends Type {
 
     public final static TypeInteger TOP = new TypeInteger(false, 0);
     public final static TypeInteger BOT = new TypeInteger(false, 1);
+    public final static TypeInteger ZERO= new TypeInteger(true, 0);
 
     private final boolean _is_con;