diff --git a/python/mozbuild/mozbuild/makeutil.py b/python/mozbuild/mozbuild/makeutil.py
index 20b494daa613..280b80c7613e 100644
--- a/python/mozbuild/mozbuild/makeutil.py
+++ b/python/mozbuild/mozbuild/makeutil.py
@@ -15,7 +15,7 @@ class Makefile(object):
     '''
 
     def __init__(self):
-        self._rules = []
+        self._statements = []
 
     def create_rule(self, targets=[]):
         '''
@@ -23,9 +23,16 @@ class Makefile(object):
         Returns the corresponding Rule instance.
         '''
         rule = Rule(targets)
-        self._rules.append(rule)
+        self._statements.append(rule)
         return rule
 
+    def add_statement(self, statement):
+        '''
+        Add a raw statement in the makefile. Meant to be used for
+        simple variable assignments.
+        '''
+        self._statements.append(statement)
+
     def dump(self, fh, removal_guard=True):
         '''
         Dump all the rules to the given file handle. Optionally (and by
@@ -34,12 +41,15 @@ class Makefile(object):
         '''
         all_deps = set()
         all_targets = set()
-        for rule in self._rules:
-            rule.dump(fh)
-            all_deps.update(rule.dependencies())
-            all_targets.update(rule.targets())
+        for statement in self._statements:
+            if isinstance(statement, Rule):
+                statement.dump(fh)
+                all_deps.update(statement.dependencies())
+                all_targets.update(statement.targets())
+            else:
+                fh.write('%s\n' % statement)
         if removal_guard:
-            guard = Rule(all_deps - all_targets)
+            guard = Rule(sorted(all_deps - all_targets))
             guard.dump(fh)
 
 
@@ -51,21 +61,23 @@ class Rule(object):
                    ...
     '''
     def __init__(self, targets=[]):
-        self._targets = set()
-        self._dependencies = set()
+        self._targets = []
+        self._dependencies = []
         self._commands = []
         self.add_targets(targets)
 
     def add_targets(self, targets):
         '''Add additional targets to the rule.'''
         assert isinstance(targets, Iterable) and not isinstance(targets, StringTypes)
-        self._targets.update(t.replace(os.sep, '/') for t in targets)
+        self._targets.extend(t.replace(os.sep, '/') for t in targets
+                             if not t in self._targets)
         return self
 
     def add_dependencies(self, deps):
         '''Add dependencies to the rule.'''
         assert isinstance(deps, Iterable) and not isinstance(deps, StringTypes)
-        self._dependencies.update(d.replace(os.sep, '/') for d in deps)
+        self._dependencies.extend(d.replace(os.sep, '/') for d in deps
+                                  if not d in self._dependencies)
         return self
 
     def add_commands(self, commands):
@@ -94,9 +106,9 @@ class Rule(object):
         '''
         if not self._targets:
             return
-        fh.write('%s:' % ' '.join(sorted(self._targets)))
+        fh.write('%s:' % ' '.join(self._targets))
         if self._dependencies:
-            fh.write(' %s' % ' '.join(sorted(self._dependencies)))
+            fh.write(' %s' % ' '.join(self._dependencies))
         fh.write('\n')
         for cmd in self._commands:
             fh.write('\t%s\n' % cmd)
diff --git a/python/mozbuild/mozbuild/test/test_makeutil.py b/python/mozbuild/mozbuild/test/test_makeutil.py
index 5c11d172c49e..38ecdb34243f 100644
--- a/python/mozbuild/mozbuild/test/test_makeutil.py
+++ b/python/mozbuild/mozbuild/test/test_makeutil.py
@@ -22,19 +22,13 @@ class TestMakefile(unittest.TestCase):
 
         rule.add_targets(['foo', 'bar'])
         rule.dump(out)
-        self.assertEqual(out.getvalue(), 'bar foo:\n')
+        self.assertEqual(out.getvalue(), 'foo bar:\n')
         out.truncate(0)
 
         rule.add_targets(['baz'])
         rule.add_dependencies(['qux', 'hoge', 'piyo'])
         rule.dump(out)
-        self.assertEqual(out.getvalue(), 'bar baz foo: hoge piyo qux\n')
-        out.truncate(0)
-
-        rule.add_targets(['baz'])
-        rule.add_dependencies(['qux', 'hoge', 'piyo'])
-        rule.dump(out)
-        self.assertEqual(out.getvalue(), 'bar baz foo: hoge piyo qux\n')
+        self.assertEqual(out.getvalue(), 'foo bar baz: qux hoge piyo\n')
         out.truncate(0)
 
         rule = Rule(['foo', 'bar'])
@@ -43,7 +37,7 @@ class TestMakefile(unittest.TestCase):
         rule.add_commands(['$(BAZ) -o $@ $<', '$(TOUCH) $@'])
         rule.dump(out)
         self.assertEqual(out.getvalue(),
-            'bar foo: baz\n' +
+            'foo bar: baz\n' +
             '\techo $@\n' +
             '\t$(BAZ) -o $@ $<\n' +
             '\t$(TOUCH) $@\n')
@@ -73,6 +67,21 @@ class TestMakefile(unittest.TestCase):
             '\techo $@\n' +
             'hoge qux:\n')
 
+    def test_statement(self):
+        out = StringIO()
+        mk = Makefile()
+        mk.create_rule(['foo']).add_dependencies(['bar']) \
+                               .add_commands(['echo foo'])
+        mk.add_statement('BAR = bar')
+        mk.create_rule(['$(BAR)']).add_commands(['echo $@'])
+        mk.dump(out, removal_guard=False)
+        self.assertEqual(out.getvalue(),
+            'foo: bar\n' +
+            '\techo foo\n' +
+            'BAR = bar\n' +
+            '$(BAR):\n' +
+            '\techo $@\n')
+
     @unittest.skipIf(os.name != 'nt', 'Test only applicable on Windows.')
     def test_path_normalization(self):
         out = StringIO()