diff --git a/Lib/linecache.py b/Lib/linecache.py
index 27883fde59e..ef2adf53693 100644
--- a/Lib/linecache.py
+++ b/Lib/linecache.py
@@ -73,13 +73,13 @@ def updatecache(filename, module_globals=None):
 
     if filename in cache:
         del cache[filename]
-    if not filename or filename[0] + filename[-1] == '<>':
+    if not filename or (filename.startswith('<') and filename.endswith('>')):
         return []
 
     fullname = filename
     try:
         stat = os.stat(fullname)
-    except os.error as msg:
+    except OSError:
         basename = filename
 
         # Try for a __loader__, if available
@@ -114,20 +114,23 @@ def updatecache(filename, module_globals=None):
                 fullname = os.path.join(dirname, basename)
             except (TypeError, AttributeError):
                 # Not sufficiently string-like to do anything useful with.
+                continue
+            try:
+                stat = os.stat(fullname)
+                break
+            except os.error:
                 pass
-            else:
-                try:
-                    stat = os.stat(fullname)
-                    break
-                except os.error:
-                    pass
         else:
-            # No luck
             return []
-    with open(fullname, 'rb') as fp:
-        coding, line = tokenize.detect_encoding(fp.readline)
-    with open(fullname, 'r', encoding=coding) as fp:
-        lines = fp.readlines()
+    try:
+        with open(fullname, 'rb') as fp:
+            coding, line = tokenize.detect_encoding(fp.readline)
+        with open(fullname, 'r', encoding=coding) as fp:
+            lines = fp.readlines()
+    except IOError:
+        pass
+    if lines and not lines[-1].endswith('\n'):
+        lines[-1] += '\n'
     size, mtime = stat.st_size, stat.st_mtime
     cache[filename] = size, mtime, lines, fullname
     return lines
diff --git a/Lib/test/test_linecache.py b/Lib/test/test_linecache.py
index 99412503788..06b6ad9b332 100644
--- a/Lib/test/test_linecache.py
+++ b/Lib/test/test_linecache.py
@@ -31,6 +31,11 @@ a = f()
 
 '''
 
+SOURCE_3 = '''
+def f():
+    return 3''' # No ending newline
+
+
 class LineCacheTests(unittest.TestCase):
 
     def test_getline(self):
@@ -63,6 +68,13 @@ class LineCacheTests(unittest.TestCase):
         empty = linecache.getlines('a/b/c/__init__.py')
         self.assertEquals(empty, [])
 
+    def test_no_ending_newline(self):
+        self.addCleanup(support.unlink, support.TESTFN)
+        with open(support.TESTFN, "w") as fp:
+            fp.write(SOURCE_3)
+        lines = linecache.getlines(support.TESTFN)
+        self.assertEqual(lines, ["\n", "def f():\n", "    return 3\n"])
+
     def test_clearcache(self):
         cached = []
         for entry in TESTS:
@@ -81,39 +93,36 @@ class LineCacheTests(unittest.TestCase):
 
     def test_checkcache(self):
         getline = linecache.getline
-        try:
-            # Create a source file and cache its contents
-            source_name = support.TESTFN + '.py'
-            with open(source_name, 'w') as source:
-                source.write(SOURCE_1)
-            getline(source_name, 1)
+        # Create a source file and cache its contents
+        source_name = support.TESTFN + '.py'
+        self.addCleanup(support.unlink, source_name)
+        with open(source_name, 'w') as source:
+            source.write(SOURCE_1)
+        getline(source_name, 1)
 
-            # Keep a copy of the old contents
-            source_list = []
-            with open(source_name) as source:
-                for index, line in enumerate(source):
-                    self.assertEquals(line, getline(source_name, index + 1))
-                    source_list.append(line)
-
-            with open(source_name, 'w') as source:
-                source.write(SOURCE_2)
-
-            # Try to update a bogus cache entry
-            linecache.checkcache('dummy')
-
-            # Check that the cache matches the old contents
-            for index, line in enumerate(source_list):
+        # Keep a copy of the old contents
+        source_list = []
+        with open(source_name) as source:
+            for index, line in enumerate(source):
                 self.assertEquals(line, getline(source_name, index + 1))
+                source_list.append(line)
 
-            # Update the cache and check whether it matches the new source file
-            linecache.checkcache(source_name)
-            with open(source_name) as source:
-                for index, line in enumerate(source):
-                    self.assertEquals(line, getline(source_name, index + 1))
-                    source_list.append(line)
+        with open(source_name, 'w') as source:
+            source.write(SOURCE_2)
 
-        finally:
-            support.unlink(source_name)
+        # Try to update a bogus cache entry
+        linecache.checkcache('dummy')
+
+        # Check that the cache matches the old contents
+        for index, line in enumerate(source_list):
+            self.assertEquals(line, getline(source_name, index + 1))
+
+        # Update the cache and check whether it matches the new source file
+        linecache.checkcache(source_name)
+        with open(source_name) as source:
+            for index, line in enumerate(source):
+                self.assertEquals(line, getline(source_name, index + 1))
+                source_list.append(line)
 
 def test_main():
     support.run_unittest(LineCacheTests)
diff --git a/Misc/NEWS b/Misc/NEWS
index 39a45fcdfb8..f700c641cce 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -393,6 +393,9 @@ C-API
 Library
 -------
 
+- Issue #8782: Add a trailing newline in linecache.updatecache to the last line
+  of files without one.
+
 - Issue #8729: Return NotImplemented from collections.Mapping.__eq__ when
   comparing to a non-mapping.