diff --git a/Lib/inspect.py b/Lib/inspect.py
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -547,16 +547,17 @@ def findsource(object):
     or code object.  The source code is returned as a list of all the lines
     in the file and the line number indexes a line in that list.  An IOError
     is raised if the source code cannot be retrieved."""
 
     file = getfile(object)
     sourcefile = getsourcefile(object)
     if not sourcefile and file[0] + file[-1] != '<>':
         raise IOError('source code not available')
+    linecache.checkcache(sourcefile)
     file = sourcefile if sourcefile else file
 
     module = getmodule(object, file)
     if module:
         lines = linecache.getlines(file, module.__dict__)
     else:
         lines = linecache.getlines(file)
     if not lines:
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -1,25 +1,29 @@
 import re
 import sys
 import types
 import unittest
+import importlib
 import inspect
 import linecache
 import datetime
 import collections
 import os
 import shutil
+import textwrap
 from os.path import normcase
 
 from test.support import run_unittest, TESTFN, DirsOnSysPath
 
 from test import inspect_fodder as mod
 from test import inspect_fodder2 as mod2
 
+from test.test_import import _ready_to_import
+
 # C module for test_findsource_binary
 import unicodedata
 
 # Functions tested in this suite:
 # ismodule, isclass, ismethod, isfunction, istraceback, isframe, iscode,
 # isbuiltin, isroutine, isgenerator, isgeneratorfunction, getmembers,
 # getdoc, getfile, getmodule, getsourcefile, getcomments, getsource,
 # getclasstree, getargspec, getargvalues, formatargspec, formatargvalues,
@@ -2263,20 +2267,50 @@ class TestBoundArguments(unittest.TestCa
         ba3.arguments['a'] = 1
         self.assertEqual(ba, ba3)
 
         def bar(b): pass
         ba4 = inspect.signature(bar).bind(1)
         self.assertNotEqual(ba, ba4)
 
 
+class TestReload(unittest.TestCase):
+
+    src_before = textwrap.dedent("""\
+def foo():
+    print("Bla")
+    """)
+
+    src_after = textwrap.dedent("""\
+def foo():
+    print("Oh no!")
+    """)
+
+    def assertInspectEqual(self, path, source):
+        inspected_src = inspect.getsource(source)
+        with open(path) as src:
+            self.assertEqual(
+                src.read().splitlines(True),
+                inspected_src.splitlines(True)
+            )
+
+    def test_getsource_reload(self):
+        # see issue 1218234
+        with _ready_to_import('reload_bug', self.src_before) as (name, path):
+            module = importlib.import_module(name)
+            self.assertInspectEqual(path, module)
+            with open(path, 'w') as src:
+                src.write(self.src_after)
+            self.assertInspectEqual(path, module)
+
+
 def test_main():
     run_unittest(
         TestDecorators, TestRetrievingSourceCode, TestOneliners, TestBuggyCases,
         TestInterpreterStack, TestClassesAndFunctions, TestPredicates,
         TestGetcallargsFunctions, TestGetcallargsMethods,
         TestGetcallargsUnboundMethods, TestGetattrStatic, TestGetGeneratorState,
         TestNoEOL, TestSignatureObject, TestSignatureBind, TestParameterObject,
-        TestBoundArguments, TestGetClosureVars
+        TestBoundArguments, TestGetClosureVars, TestReload,
     )
 
 if __name__ == "__main__":
     test_main()