diff --git a/server.py b/server.py
index 1f617d2..3d3231f 100644
--- a/server.py
+++ b/server.py
@@ -73,6 +73,10 @@ def alter(partID):
         if len(request.files) != 0:
             datasheet_file = request.files['datasheet-file']
             datasheet_filename = secure_filename(datasheet_file.filename)
+            i = 1
+            while os.path.isfile('srv/datasheet/' + datasheet_filename):
+                datasheet_filename = datasheet_filename[:-4] + str(i) + '.pdf'
+                i += 1
             datasheet_file.save('/srv/datasheets/' + datasheet_filename)
         else:
             datasheet_filename = None
@@ -97,6 +101,10 @@ def alter(partID):
         if len(request.files) != 0:
             datasheet_file = request.files['datasheet-file']
             datasheet_filename = secure_filename(datasheet_file.filename)
+            i = 1
+            while os.path.isfile('srv/datasheet/' + datasheet_filename):
+                datasheet_filename = datasheet_filename[:-4] + str(i) + '.pdf'
+                i += 1
             datasheet_file.save('/srv/datasheets/' + datasheet_filename)
             if l[0]['datasheet'] != None:
                 os.remove('/srv/datasheets/' + l[0]['datasheet'])