diff --git a/lib/validate.js b/lib/validate.js
index dc95adf..137bfeb 100644
--- a/lib/validate.js
+++ b/lib/validate.js
@@ -248,6 +248,18 @@ Vp.returnType = function returnType(stmt) {
             return ty.Double;
         });
 
+        when({
+            type: 'UnaryExpression',
+            operator: '-',
+            argument: {
+                type: 'Literal',
+                value: match.number,
+                raw: hasDot
+            }
+        }, function() {
+            return ty.Double;
+        });
+
         when({
             type: 'Literal',
             value: match.all(match.number,
@@ -256,6 +268,19 @@ Vp.returnType = function returnType(stmt) {
         }, function() {
             return ty.Signed;
         });
+
+        when({
+            type: 'UnaryExpression',
+            operator: '-',
+            argument: {
+                type: 'Literal',
+                value: match.all(match.number,
+                                 match.range(0, 0x80000001)),
+                raw: dotless
+            }
+        }, function() {
+            return ty.Signed;
+        });
     });
 };
 
@@ -471,12 +496,36 @@ Vp.local = function local(x, rhs) {
             return ty.Double;
         }, this);
 
+        when({
+            type: 'UnaryExpression',
+            operator: '-',
+            argument: {
+                type: 'Literal',
+                value: match.number,
+                raw: hasDot
+            }
+        }, function() {
+            return ty.Double;
+        });
+
         when({
             type: 'Literal',
             value: match.all(match.integer, match.range(-0x80000000, 0x100000000))
         }, function(vars) {
             return ty.Int;
         }, this);
+
+        when({
+            type: 'UnaryExpression',
+            operator: '-',
+            argument: {
+                type: 'Literal',
+                value: match.all(match.number, match.range(0, 0x80000001)),
+                raw: dotless
+            }
+        }, function() {
+            return ty.Int;
+        });
     });
 };
 
@@ -894,6 +943,19 @@ Vp.expression = function expression(e) {
             return this.expression(last);
         }, this);
 
+        when({
+            type: 'UnaryExpression',
+            operator: '-',
+            argument: {
+                type: 'Literal',
+                value: match.all(match.number,
+                                 match.range(0, 0x80000001)),
+                raw: dotless
+            }
+        }, function(vars) {
+            return ty.Signed;
+        }, this);
+
         when({
             type: 'UnaryExpression',
             operator: '~',
diff --git a/test/index.js b/test/index.js
index a787115..ba70407 100644
--- a/test/index.js
+++ b/test/index.js
@@ -354,3 +354,31 @@ exports.testForWithoutUpdate = asmAssert.one(
         }
     },
     { pass: true });
+
+exports.testNegativeIntReturn = asmAssert.one(
+    "negative integer literal as return value",
+    function f() {
+        return -42;
+    },
+    { pass: true });
+
+exports.testNegativeDoubleReturn = asmAssert.one(
+    "negative double literal as return value",
+    function f() {
+        return -42.1;
+    },
+    { pass: true });
+
+exports.testNegativeIntVar = asmAssert.one(
+    "negative integer literal as variable declaration",
+    function f() {
+        var i = -42;
+    },
+    { pass: true });
+
+exports.testNegativeDoubleVar = asmAssert.one(
+    "negative double literal as variable declaration",
+    function f() {
+        var i = -42.1;
+    },
+    { pass: true });