diff --git a/src/main/java/com/redhat/ceylon/compiler/js/ForGenerator.java b/src/main/java/com/redhat/ceylon/compiler/js/ForGenerator.java
index 355500f5..e1507192 100644
--- a/src/main/java/com/redhat/ceylon/compiler/js/ForGenerator.java
+++ b/src/main/java/com/redhat/ceylon/compiler/js/ForGenerator.java
@@ -88,8 +88,8 @@ boolean optimizeRange(final Tree.RangeOp range, final String itemVar) {
         final Tree.Term right = range.getRightTerm();
         if (left instanceof Tree.NaturalLiteral && right instanceof NaturalLiteral) {
             try {
-                long una = gen.parseNaturalLiteral((Tree.NaturalLiteral)left);
-                long dos = gen.parseNaturalLiteral((Tree.NaturalLiteral)right);
+                long una = gen.parseNaturalLiteral((Tree.NaturalLiteral)left, false);
+                long dos = gen.parseNaturalLiteral((Tree.NaturalLiteral)right, false);
                 optimizeNaturals(una, dos, itemVar);
                 return true;
             } catch (NumberFormatException ex) {
@@ -118,15 +118,15 @@ boolean optimizeSegment(Tree.SegmentOp that, final String itemVar) {
         final boolean rightNat = right instanceof Tree.NaturalLiteral;
         if (leftNat && rightNat) {
             try {
-                long una = gen.parseNaturalLiteral((Tree.NaturalLiteral)left);
-                long dos = gen.parseNaturalLiteral((Tree.NaturalLiteral)right);
+                long una = gen.parseNaturalLiteral((Tree.NaturalLiteral)left, false);
+                long dos = gen.parseNaturalLiteral((Tree.NaturalLiteral)right, false);
                 optimizeNaturals(una, una+dos-1, itemVar);
                 return true;
             } catch (NumberFormatException ex) {
                 return false;
             }
         }
-        final String limvar = rightNat ? Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)right))
+        final String limvar = rightNat ? Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)right, false))
                 : gen.getNames().createTempVariable();
         gen.out("var ", itemVar, "=");
         left.visit(gen);
diff --git a/src/main/java/com/redhat/ceylon/compiler/js/GenerateJsVisitor.java b/src/main/java/com/redhat/ceylon/compiler/js/GenerateJsVisitor.java
index 8d768522..a1ae0c68 100644
--- a/src/main/java/com/redhat/ceylon/compiler/js/GenerateJsVisitor.java
+++ b/src/main/java/com/redhat/ceylon/compiler/js/GenerateJsVisitor.java
@@ -1554,17 +1554,22 @@ public void visit(final Tree.FloatLiteral that) {
         out(getClAlias(), "Float(", that.getText(), ")");
     }
 
-    public long parseNaturalLiteral(Tree.NaturalLiteral that) throws NumberFormatException {
-        char prefix = that.getText().charAt(0);
-        int radix = 10;
+    long parseNaturalLiteral(Tree.NaturalLiteral that, boolean neg) throws NumberFormatException {
         String nt = that.getText();
+        char prefix = nt.charAt(0);
+        int radix = 10;
         if (prefix == '$' || prefix == '#') {
             radix = prefix == '$' ? 2 : 16;
             nt = nt.substring(1);
         }
         final java.math.BigInteger lit = new java.math.BigInteger(nt, radix);
-        if (lit.bitLength() > 63) {
-            that.addError("Natural literal outside the valid range (-9223372036854775808..9223372036854775807)");
+        if (radix==10 && lit.bitLength() > 63) {
+            if (lit.bitLength() == 64 && neg) {
+                return -lit.longValue();
+            }
+            that.addError("literal outside representable range: " + nt + " is too large to be represented as an Integer");
+        } else if (lit.bitLength() > 63 && lit.bitLength()==lit.bitCount()) {
+            out("/*bit length=" + lit.bitLength() + ", count=" + lit.bitCount(), " ERGO " + (lit.longValue()),"*/");
         }
         return lit.longValue();
     }
@@ -1572,7 +1577,7 @@ public long parseNaturalLiteral(Tree.NaturalLiteral that) throws NumberFormatExc
     @Override
     public void visit(final Tree.NaturalLiteral that) {
         try {
-            out("(", Long.toString(parseNaturalLiteral(that)), ")");
+            out("(", Long.toString(parseNaturalLiteral(that, false)), ")");
         } catch (NumberFormatException ex) {
             that.addError("Invalid numeric literal " + that.getText());
         }
@@ -2630,12 +2635,13 @@ private void assignOp(final Tree.AssignmentOp that, final String functionName, f
 
     @Override public void visit(final Tree.NegativeOp that) {
         if (that.getTerm() instanceof Tree.NaturalLiteral) {
-            long t = parseNaturalLiteral((Tree.NaturalLiteral)that.getTerm());
+            long t = parseNaturalLiteral((Tree.NaturalLiteral)that.getTerm(), true);
             out("(");
             if (t > 0) {
-                out("-");
+                out("-", Long.toString(t));
+            } else {
+                out(Long.toString(-t));
             }
-            out(Long.toString(t));
             out(")");
             if (t == 0) {
                 //Force -0
@@ -3406,7 +3412,10 @@ public int getExitCode() {
 
     boolean isNaturalLiteral(Tree.Term that) {
         if (that instanceof Tree.NaturalLiteral) {
-            out(Long.toString(parseNaturalLiteral((Tree.NaturalLiteral)that)));
+            out(Long.toString(parseNaturalLiteral((Tree.NaturalLiteral)that, false)));
+            return true;
+        } else if (that instanceof Tree.NegativeOp) {
+            that.visit(this);
             return true;
         }
         return false;
diff --git a/src/main/java/com/redhat/ceylon/compiler/js/Operators.java b/src/main/java/com/redhat/ceylon/compiler/js/Operators.java
index 1f75c97b..d5d615ed 100644
--- a/src/main/java/com/redhat/ceylon/compiler/js/Operators.java
+++ b/src/main/java/com/redhat/ceylon/compiler/js/Operators.java
@@ -16,13 +16,13 @@ static void simpleBinaryOp(final Tree.BinaryOperatorExpression exp,
             gen.out(before);
         }
         if (op.charAt(0)!='.' && exp.getLeftTerm() instanceof Tree.NaturalLiteral) {
-            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getLeftTerm())));
+            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getLeftTerm(), false)));
         } else {
             gen.box(exp.getLeftTerm());
         }
         gen.out(op);
         if (exp.getRightTerm() instanceof Tree.NaturalLiteral) {
-            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getRightTerm())));
+            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getRightTerm(), false)));
         } else {
             gen.box(exp.getRightTerm());
         }
@@ -35,13 +35,13 @@ static void genericBinaryOp(final Tree.BinaryOperatorExpression exp, final Strin
             final Map<TypeParameter, ProducedType> targs, final Map<TypeParameter, SiteVariance> overrides,
             final GenerateJsVisitor gen) {
         if (op.charAt(0)!='.' && exp.getLeftTerm() instanceof Tree.NaturalLiteral) {
-            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getLeftTerm())));
+            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getLeftTerm(), false)));
         } else {
             gen.box(exp.getLeftTerm());
         }
         gen.out(op);
         if (exp.getRightTerm() instanceof Tree.NaturalLiteral) {
-            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getRightTerm())));
+            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getRightTerm(), false)));
         } else {
             gen.box(exp.getRightTerm());
         }
@@ -58,7 +58,7 @@ static void unaryOp(final Tree.UnaryOperatorExpression exp, final String before,
             gen.out(before);
         }
         if ((after==null || after.charAt(0)!='.' ) && exp.getTerm() instanceof Tree.NaturalLiteral) {
-            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getTerm())));
+            gen.out(Long.toString(gen.parseNaturalLiteral((Tree.NaturalLiteral)exp.getTerm(), false)));
         } else {
             final int boxTypeLeft = gen.boxStart(exp.getTerm());
             exp.getTerm().visit(gen);