diff --git a/pyls/plugins/highlight.py b/pyls/plugins/highlight.py
index 8d052173..adc06b01 100644
--- a/pyls/plugins/highlight.py
+++ b/pyls/plugins/highlight.py
@@ -9,6 +9,9 @@
 def pyls_document_highlight(document, position):
     usages = document.jedi_script(position).usages()
 
+    def is_valid(definition):
+        return definition.line is not None and definition.column is not None
+
     def local_to_document(definition):
         return not definition.module_path or uris.uri_with(document.uri, path=definition.module_path) == document.uri
 
@@ -18,4 +21,4 @@ def local_to_document(definition):
             'end': {'line': d.line - 1, 'character': d.column + len(d.name)}
         },
         'kind': lsp.DocumentHighlightKind.Write if d.is_definition() else lsp.DocumentHighlightKind.Read
-    } for d in usages if local_to_document(d)]
+    } for d in usages if is_valid(d) and local_to_document(d)]
diff --git a/test/plugins/test_highlight.py b/test/plugins/test_highlight.py
index 947c16e1..41e9075b 100644
--- a/test/plugins/test_highlight.py
+++ b/test/plugins/test_highlight.py
@@ -30,3 +30,27 @@ def test_highlight():
         # The second usage is Read
         'kind': lsp.DocumentHighlightKind.Read
     }]
+
+
+SYS_DOC = '''import sys
+print sys.path
+'''
+
+
+def test_sys_highlight():
+    cursor_pos = {'line': 0, 'character': 8}
+
+    doc = Document(DOC_URI, SYS_DOC)
+    assert pyls_document_highlight(doc, cursor_pos) == [{
+        'range': {
+            'start': {'line': 0, 'character': 7},
+            'end': {'line': 0, 'character': 10}
+        },
+        'kind': lsp.DocumentHighlightKind.Write
+    }, {
+        'range': {
+            'start': {'line': 1, 'character': 6},
+            'end': {'line': 1, 'character': 9}
+        },
+        'kind': lsp.DocumentHighlightKind.Read
+    }]