diff --git a/src/util.js b/src/util.js
index f688693..1d96eae 100644
--- a/src/util.js
+++ b/src/util.js
@@ -58,7 +58,7 @@ const createShouldIgnore = options => {
   }
 }
 
-const isNegative = pattern => pattern[0] === '!'
+const isNegative = pattern => pattern[0] === '!' && pattern[1] !== '('
 const isPattern = subject => subject && typeof subject === 'string'
 
 const createTasks = (patterns, options) => {
diff --git a/test/fixtures/b/a.js b/test/fixtures/b/a.js
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/b/b.js b/test/fixtures/b/b.js
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/b/b/a.js b/test/fixtures/b/b/a.js
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/b/b/b.js b/test/fixtures/b/b/b.js
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/b/b/b/a.js b/test/fixtures/b/b/b/a.js
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/b/b/b/b.js b/test/fixtures/b/b/b/b.js
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/b/b/b/c b/test/fixtures/b/b/b/c
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/b/b/c b/test/fixtures/b/b/c
new file mode 100644
index 0000000..e69de29
diff --git a/test/fixtures/b/c b/test/fixtures/b/c
new file mode 100644
index 0000000..e69de29
diff --git a/test/glob-gitignore.js b/test/glob-gitignore.js
index ec1b660..b326cb8 100644
--- a/test/glob-gitignore.js
+++ b/test/glob-gitignore.js
@@ -16,7 +16,7 @@ const CASES = [
     d: 'basic',
     p: '**/*.js',
     i: 'a.js',
-    r: ['b.js', 'a/b.js', 'a/a/b.js', 'a/a/a/b.js']
+    r: ['b.js', 'a/b.js', 'a/a/b.js', 'a/a/a/b.js', 'b/b.js', 'b/b/b.js', 'b/b/b/b.js']
   },
   {
     d: 'patterns',
@@ -33,12 +33,17 @@ const CASES = [
   {
     d: 'without ignore',
     p: ['**/a.js'],
-    r: ['a.js', 'a/a.js', 'a/a/a.js', 'a/a/a/a.js']
+    r: ['a.js', 'a/a.js', 'a/a/a.js', 'a/a/a/a.js', 'b/a.js', 'b/b/a.js', 'b/b/b/a.js']
   },
   {
     d: 'only negative',
     p: ['!**/a.js'],
     r: []
+  },
+  {
+    d: 'negative prefixed group',
+    p: '!(a)**/*.js',
+    r: ['b/b.js', 'b/a.js']
   }
 ]