diff --git a/fdroidserver/common.py b/fdroidserver/common.py
index ca02219f..75eac97c 100644
--- a/fdroidserver/common.py
+++ b/fdroidserver/common.py
@@ -55,6 +55,8 @@ from .asynchronousfilereader import AsynchronousFileReader
 
 # A signature block file with a .DSA, .RSA, or .EC extension
 CERT_PATH_REGEX = re.compile(r'^META-INF/.*\.(DSA|EC|RSA)$')
+APK_NAME_REGEX = re.compile(r'^([a-zA-Z][\w.]*)_(-?[0-9]+)_?([0-9a-f]{7})?\.apk')
+STANDARD_FILE_NAME_REGEX = re.compile(r'^(\w[\w.]*)_(-?[0-9]+)\.\w+')
 
 XMLElementTree.register_namespace('android', 'http://schemas.android.com/apk/res/android')
 
diff --git a/fdroidserver/update.py b/fdroidserver/update.py
index caea795b..c36fd86e 100644
--- a/fdroidserver/update.py
+++ b/fdroidserver/update.py
@@ -853,14 +853,10 @@ def scan_repo_files(apkcache, repodir, knownapks, use_date_from_file=False):
             # the static ID is the SHA256 unless it is set in the metadata
             repo_file['packageName'] = shasum
 
-            n = name_utf8.rsplit('_', maxsplit=1)
-            if len(n) == 2:
-                packageName = n[0]
-                versionCode = n[1].split('.')[0]
-                if re.match('^-?[0-9]+$', versionCode) \
-                   and common.is_valid_package_name(n[0]):
-                    repo_file['packageName'] = packageName
-                    repo_file['versionCode'] = int(versionCode)
+            m = common.STANDARD_FILE_NAME_REGEX.match(name_utf8)
+            if m:
+                repo_file['packageName'] = m.group(1)
+                repo_file['versionCode'] = int(m.group(2))
             srcfilename = name + b'_src.tar.gz'
             if os.path.exists(os.path.join(repodir, srcfilename)):
                 repo_file['srcname'] = srcfilename.decode('utf-8')
diff --git a/tests/common.TestCase b/tests/common.TestCase
index 74364098..f0dcacce 100755
--- a/tests/common.TestCase
+++ b/tests/common.TestCase
@@ -281,6 +281,70 @@ class CommonTest(unittest.TestCase):
                 key = "val"
                 """))
 
+    def test_apk_name_regex(self):
+        good = [
+            'urzipπÇÇπÇÇ现代汉语通用字българскиعربي1234ö_-123456.apk',
+            'urzipπÇÇπÇÇ现代汉语通用字българскиعربي1234ö_123456_abcdef0.apk',
+            'urzip_-123456.apk',
+            'a0_0.apk',
+            'Z0_0.apk',
+            'a0_0_abcdef0.apk',
+            'a_a_a_a_0_abcdef0.apk',
+            'a_____0.apk',
+            'a_____123456_abcdef0.apk',
+            'org.fdroid.fdroid_123456.apk',
+            # valid, but "_99999" is part of packageName rather than versionCode
+            'org.fdroid.fdroid_99999_123456.apk',
+            # should be valid, but I can't figure out the regex since \w includes digits
+            # 'πÇÇπÇÇ现代汉语通用字българскиعربي1234ö_0_123bafd.apk',
+        ]
+        for name in good:
+            m = fdroidserver.common.APK_NAME_REGEX.match(name)
+            self.assertIsNotNone(m)
+            self.assertIn(m.group(2), ('-123456', '0', '123456'))
+            self.assertIn(m.group(3), ('abcdef0', None))
+
+        bad = [
+            'urzipπÇÇπÇÇ现代汉语通用字българскиعربي1234ö_123456_abcdefg.apk',
+            'urzip-_-198274.apk',
+            'urzip-_0_123bafd.apk',
+            'no spaces allowed_123.apk',
+            '0_0.apk',
+            '0_0_abcdef0.apk',
+        ]
+        for name in bad:
+            self.assertIsNone(fdroidserver.common.APK_NAME_REGEX.match(name))
+
+    def test_standard_file_name_regex(self):
+        good = [
+            'urzipπÇÇπÇÇ现代汉语通用字българскиعربي1234ö_-123456.mp3',
+            'urzipπÇÇπÇÇ现代汉语通用字българскиعربي1234ö_123456.mov',
+            'Document_-123456.pdf',
+            'WTF_0.MOV',
+            'Z0_0.ebk',
+            'a_a_a_a_0.txt',
+            'org.fdroid.fdroid.privileged.ota_123456.zip',
+            'πÇÇπÇÇ现代汉语通用字българскиعربي1234ö_0.jpeg',
+            'a_____0.PNG',
+            # valid, but "_99999" is part of packageName rather than versionCode
+            'a_____99999_123456.zip',
+            'org.fdroid.fdroid_99999_123456.zip',
+        ]
+        for name in good:
+            m = fdroidserver.common.STANDARD_FILE_NAME_REGEX.match(name)
+            self.assertIsNotNone(m)
+            self.assertIn(m.group(2), ('-123456', '0', '123456'))
+
+        bad = [
+            'urzipπÇÇπÇÇ现代汉语通用字българскиعربي1234ö_abcdefg.JPEG',
+            'urzip-_-198274.zip',
+            'urzip-_123bafd.pdf',
+            'no spaces allowed_123.foobar',
+            'a_____0.',
+        ]
+        for name in bad:
+            self.assertIsNone(fdroidserver.common.STANDARD_FILE_NAME_REGEX.match(name))
+
 
 if __name__ == "__main__":
     parser = optparse.OptionParser()
diff --git a/tests/stats/known_apks.txt b/tests/stats/known_apks.txt
index ec777242..329213b7 100644
--- a/tests/stats/known_apks.txt
+++ b/tests/stats/known_apks.txt
@@ -1,4 +1,4 @@
-fake.ota.update_1234.zip 897a92a4ccff4f415f6ba275b2af16d4ecaee60a983b215bddcb9f8964e7a24c 2016-03-10
+fake.ota.update_1234.zip fake.ota.update 2016-03-10
 obb.main.oldversion_1444412523.apk obb.main.oldversion 2013-12-31
 obb.main.twoversions_1101613.apk obb.main.twoversions 2015-10-12
 obb.main.twoversions_1101615.apk obb.main.twoversions 2016-01-01