--- a/python/mozlint/mozlint/pathutils.py
+++ b/python/mozlint/mozlint/pathutils.py
@@ -67,22 +67,28 @@ def filterpaths(paths, linter, **lintarg
     :param paths: A starting list of paths to possibly lint.
     :param linter: A linter definition.
     :param lintargs: Extra arguments passed to the linter.
     :returns: A list of file paths to lint.
     """
     include = linter.get('include', [])
     exclude = lintargs.get('exclude', [])
     exclude.extend(linter.get('exclude', []))
+    root = lintargs['root']
 
     if not lintargs.get('use_filters', True) or (not include and not exclude):
         return paths
 
-    include = map(FilterPath, include or [])
-    exclude = map(FilterPath, exclude or [])
+    def normalize(path):
+        if not os.path.isabs(path):
+            path = os.path.join(root, path)
+        return FilterPath(path)
+
+    include = map(normalize, include)
+    exclude = map(normalize, exclude)
 
     # Paths with and without globs will be handled separately,
     # pull them apart now.
     includepaths = [p for p in include if p.exists]
     excludepaths = [p for p in exclude if p.exists]
 
     includeglobs = [p for p in include if not p.exists]
     excludeglobs = [p for p in exclude if not p.exists]

--- a/python/mozlint/mozlint/roller.py
+++ b/python/mozlint/mozlint/roller.py
@@ -104,16 +104,17 @@ class LintRoller(object):
             raise LintersNotConfigured
 
         # Calculate files from VCS
         if rev:
             paths.extend(self.vcs.by_rev(rev))
         if workdir:
             paths.extend(self.vcs.by_workdir())
         paths = paths or ['.']
+        paths = map(os.path.abspath, paths)
 
         # Set up multiprocessing
         m = Manager()
         queue = m.Queue()
 
         for linter in self.linters:
             queue.put(linter['path'])