diff --git a/sphinx/environment.py b/sphinx/environment.py
index 86fb1b80c..c28eae940 100644
--- a/sphinx/environment.py
+++ b/sphinx/environment.py
@@ -494,7 +494,7 @@ class BuildEnvironment:
             config.exclude_trees +
             [d + config.source_suffix for d in config.unused_docs] +
             ['**/' + d for d in config.exclude_dirnames] +
-            ['**/_sources']
+            ['**/_sources', '.#*']
         )
         self.found_docs = set(get_matching_docs(
             self.srcdir, config.source_suffix, exclude_matchers=matchers))
diff --git a/sphinx/util/__init__.py b/sphinx/util/__init__.py
index b1a3a0d7d..0721118e7 100644
--- a/sphinx/util/__init__.py
+++ b/sphinx/util/__init__.py
@@ -209,6 +209,8 @@ def get_module_source(modname):
     lfilename = filename.lower()
     if lfilename.endswith('.pyo') or lfilename.endswith('.pyc'):
         filename = filename[:-1]
+        if not path.isfile(filename) and path.isfile(filename + 'w'):
+            filename += 'w'
     elif not (lfilename.endswith('.py') or lfilename.endswith('.pyw')):
         raise PycodeError('source is not a .py file: %r' % filename)
     if not path.isfile(filename):