diff --git a/rplugin/python3/deoplete/sources/ale.py b/rplugin/python3/deoplete/sources/ale.py
index 66a09551..3955ed2d 100644
--- a/rplugin/python3/deoplete/sources/ale.py
+++ b/rplugin/python3/deoplete/sources/ale.py
@@ -30,6 +30,7 @@ class Source(Base):
             '_': r'\.\w*$',
             'rust': r'(\.|::)\w*$',
             'typescript': r'(\.|\'|")\w*$',
+            'cpp': r'(\.|::|->)\w*$',
         }
 
     # Returns an integer for the start position, as with omnifunc.
diff --git a/test/python/test_deoplete_source.py b/test/python/test_deoplete_source.py
index 280df2e3..9e56a10d 100644
--- a/test/python/test_deoplete_source.py
+++ b/test/python/test_deoplete_source.py
@@ -45,6 +45,7 @@ class DeopleteSourceTest(unittest.TestCase):
                 '_': r'\.\w*$',
                 'rust': r'(\.|::)\w*$',
                 'typescript': r'(\.|\'|")\w*$',
+                'cpp': r'(\.|::|->)\w*$',
             },
             'is_bytepos': True,
             'mark': '[L]',