diff --git a/lib/jsdoc/tag.js b/lib/jsdoc/tag.js
index 32808562..b7b479cf 100644
--- a/lib/jsdoc/tag.js
+++ b/lib/jsdoc/tag.js
@@ -66,10 +66,14 @@ exports.Tag = function(tagTitle, tagBody, meta) {
             
             var tagType = jsdoc.tag.type.parse(this.text, tagDef.canHaveName, tagDef.canHaveType);
 
-            if (tagType.type && tagType.type.length) {
-                this.value.type = {
-                    names: tagType.type
-                };
+            // BUG: a tag can *not* have a type but still have optional, nullable, variable, defaultvalue.
+            // e.g. @param [foo]  has name 'foo' and property optional=true but *no type*.
+            if (tagType.type) {
+                if (tagType.type.length) {
+                    this.value.type = {
+                        names: tagType.type
+                    };
+                }
                 this.value.optional = tagType.optional;
                 this.value.nullable = tagType.nullable;
                 this.value.variable = tagType.variable;
diff --git a/test/fixtures/paramtag.js b/test/fixtures/paramtag.js
index db431bfc..c6fd831c 100644
--- a/test/fixtures/paramtag.js
+++ b/test/fixtures/paramtag.js
@@ -39,3 +39,9 @@ function split(delimiter) {
 */
 function commit(atomic) {
 }
+
+/**
+ * @param [async=true] - whether to be asynchronous
+ */
+function request(async) {
+}
diff --git a/test/specs/jsdoc/tag.js b/test/specs/jsdoc/tag.js
index e40a55a5..52d6938a 100644
--- a/test/specs/jsdoc/tag.js
+++ b/test/specs/jsdoc/tag.js
@@ -24,6 +24,7 @@ describe("jsdoc/tag", function() {
                      ' * myFunction(1, 2); // returns 3\n' +
                      ' * myFunction(3, 4); // returns 7\n';
         var tagArg = new jsdoc.tag.Tag('arg  ', text, meta), // <-- a symonym of param, space in the title.
+            tagParam = new jsdoc.tag.Tag('param', '[foo=1]', meta), // no type, but has optional and defaultvalue.
             tagEg  = new jsdoc.tag.Tag('example', textEg, meta), // <-- for keepsWhitespace
             tagType = new jsdoc.tag.Tag('type', 'MyType ', meta); // <-- for onTagText
 
@@ -101,15 +102,18 @@ describe("jsdoc/tag", function() {
                         expect(tag.value[prop]).toEqual(info[prop]);
                     }
                 }
-                expect(tag.value.type).toBeDefined();
-                expect(typeof tag.value.type).toEqual('object');
-                expect(tag.value.type.names).toBeDefined();
-                expect(tag.value.type.names).toEqual(info.type);
+                if (info.type && info.type.length) {
+                    expect(tag.value.type).toBeDefined();
+                    expect(typeof tag.value.type).toEqual('object');
+                    expect(tag.value.type.names).toBeDefined();
+                    expect(tag.value.type.names).toEqual(info.type);
+                }
             }
             it("if the tag has a type, tag.value should contain the type information", function() {
                 // we assume jsdoc/tag/type.parse works (it has its own tests to verify this);
                 verifyTagType(tagType);
                 verifyTagType(tagArg);
+                verifyTagType(tagParam);
             });
 
             it("if the tag has a description beyond the name/type, this should be in tag.value.description", function() {
diff --git a/test/specs/jsdoc/tag/type.js b/test/specs/jsdoc/tag/type.js
index 5f985b33..c9953133 100644
--- a/test/specs/jsdoc/tag/type.js
+++ b/test/specs/jsdoc/tag/type.js
@@ -122,6 +122,10 @@ describe("jsdoc/tag/type", function() {
             desc = "{string=} [foo]";
             info = jsdoc.tag.type.parse(desc, true, true);
             expect(info.optional).toEqual(true);
+
+            desc = "[foo]";
+            info = jsdoc.tag.type.parse(desc, true, true);
+            expect(info.optional).toEqual(true);
         });
         
         it("should return the types as an array", function() {
diff --git a/test/specs/tags/paramtag.js b/test/specs/tags/paramtag.js
index 14d628ad..b0e1046c 100644
--- a/test/specs/tags/paramtag.js
+++ b/test/specs/tags/paramtag.js
@@ -6,7 +6,8 @@ describe("@param tag", function() {
         getElement = docSet.getByLongname('getElement')[0],
         combine = docSet.getByLongname('combine')[0],
         split = docSet.getByLongname('split')[0],
-        commit = docSet.getByLongname('commit')[0];
+        commit = docSet.getByLongname('commit')[0],
+        request = docSet.getByLongname('request')[0];
 
     it('When a symbol has an @param tag with a type before the name, the doclet has a params property that includes that param.', function() {
         expect(typeof find.params).toEqual('object');
@@ -62,7 +63,18 @@ describe("@param tag", function() {
         expect(commit.params[0].description).toEqual('If true make the commit atomic.');
     });
 
+    it('When a symbol has a @param tag with no type but a name that indicates a default value or optional type, this infor is copied over to the params property.', function() {
+        expect(typeof request.params).toEqual('object');
+        expect(request.params.length).toEqual(1);
+        expect(request.params[0].type).toBeUndefined();
+        expect(request.params[0].name).toBe('async');
+        expect(request.params[0].defaultvalue).toBe('true');
+        expect(request.params[0].optional).toBe(true);
+        expect(request.params[0].description).toEqual('whether to be asynchronous');
+    });
+
     it('When a symbol has an @param tag with no name and a name is given in the code, the doclet has a params property that includes that param with the name from the code.', function() {
         expect(commit.params[0].name).toEqual('atomic');
     });
-});
\ No newline at end of file
+
+});