diff --git a/fdroidserver/common.py b/fdroidserver/common.py
index acccf63a..b07f080d 100644
--- a/fdroidserver/common.py
+++ b/fdroidserver/common.py
@@ -1511,7 +1511,7 @@ def parse_androidmanifests(paths, app):
     if max_version is None:
         max_version = "Unknown"
 
-    if max_package and not is_valid_package_name(max_package):
+    if max_package and not is_valid_java_package_name(max_package):
         raise FDroidException(_("Invalid package name {0}").format(max_package))
 
     return (max_version, max_vercode, max_package)
diff --git a/fdroidserver/update.py b/fdroidserver/update.py
index a760a078..635f48ee 100644
--- a/fdroidserver/update.py
+++ b/fdroidserver/update.py
@@ -1064,6 +1064,10 @@ def scan_apk(apk_file):
     else:
         scan_apk_aapt(apk, apk_file)
 
+    if not common.is_valid_java_package_name(apk['packageName']):
+        raise BuildException(_("{appid} from {path} is not a valid Java Package Name!")
+                             .format(appid=apk['packageName'], path=apk_file))
+
     # Get the signature, or rather the signing key fingerprints
     logging.debug('Getting signature of {0}'.format(os.path.basename(apk_file)))
     apk['sig'] = getsig(apk_file)