diff --git a/lib/options/unitless-zero.js b/lib/options/unitless-zero.js
new file mode 100644
index 00000000..62bb9a0c
--- /dev/null
+++ b/lib/options/unitless-zero.js
@@ -0,0 +1,82 @@
+module.exports = {
+    name: 'unitless-zero',
+
+    syntax: ['css', 'less', 'sass', 'scss'],
+
+    accepts: { boolean: [true] },
+
+    /**
+     * Processes tree node.
+     *
+     * @param {node} node
+     */
+    process: function(node) {
+        var UNITS = ['cm', 'em', 'ex', 'pt', 'px'];
+
+        if (!node.is('value') && !node.is('braces')) return;
+
+        node.forEach(function(value) {
+            if (typeof value === 'string') return;
+
+            if (value.is('dimension')) {
+                var unit = value.first('ident').content;
+                if (value.first('number').content[0] === '0' &&
+                    UNITS.indexOf(unit) !== -1) {
+                    value.remove(1);
+                }
+            } else if (value.is('percentage')) {
+                // XXX(tonyganch): There is a bug in Gonzales when in Less,
+                // percentage's content is not wrapped as an array but actually
+                // type of node's content is object. This bug has already been
+                // fixed in newer versions of Gonzales so the issue should be
+                // gone after update of dependencies and csscomb@4.0 release.
+                // This hack is here as a hotfix for csscomb@3.1 and must be
+                // removed once csscom@4.0 is released. See #389.
+                var number;
+                if (!Array.isArray(value.content) &&
+                    value.content.is('number')) {
+                    number = value.content;
+                } else {
+                    number = value.first('number').content;
+                }
+
+                if (number[0] === '0') {
+                    value.type = 'number';
+                    value.content = number;
+                }
+            }
+        });
+    },
+
+    /**
+     * Detects the value of an option at the tree node.
+     *
+     * @param {node} node
+     */
+    detect: function(node) {
+        var result;
+
+        // If we see a zero with unit and it is not degree, then we don’t have an option
+
+        if (node.is('percentage') && node.first('number').content[1] === '0') {
+            result = false;
+        } else if (node.is('dimension') &&
+                   node.first('number').content[0] === '0' &&
+                   node.first('ident').content !== 'deg') {
+            result = false;
+        }
+
+        // If we see a zero and previous node is not percentage or dimension, then we have an option
+        if (node.is('number') &&
+            node.content[0] === '0' &&
+            this._prev !== 'percentage' &&
+            this._prev !== 'dimension') {
+            result = true;
+        }
+
+        // Store the previous nodeType
+        this._prev = node.type;
+
+        return result;
+    }
+};
diff --git a/test/options/unitless-zero-less/issue-389.less b/test/options/unitless-zero-less/issue-389.less
new file mode 100644
index 00000000..f0626d68
--- /dev/null
+++ b/test/options/unitless-zero-less/issue-389.less
@@ -0,0 +1,4 @@
+.test
+{
+    width: 100%;
+}
diff --git a/test/options/unitless-zero-less/test.js b/test/options/unitless-zero-less/test.js
new file mode 100644
index 00000000..942206b9
--- /dev/null
+++ b/test/options/unitless-zero-less/test.js
@@ -0,0 +1,6 @@
+describe('options/unitless-zero (less)', function() {
+    it('Issue 389', function() {
+        this.comb.configure({ 'unitless-zero': true });
+        this.shouldBeEqual('issue-389.less');
+    });
+});