diff --git a/scripts/stack_core.py b/scripts/stack_core.py
index 6801fa1e6..22997bfb6 100755
--- a/scripts/stack_core.py
+++ b/scripts/stack_core.py
@@ -261,7 +261,8 @@ class TraceConverter:
       print("Cannot find apk", apk)
       return None, None
 
-    cmd = subprocess.Popen(["zipinfo", "-v", apk_full_path], stdout=subprocess.PIPE)
+    cmd = subprocess.Popen(["zipinfo", "-v", apk_full_path], stdout=subprocess.PIPE,
+                           encoding='utf8')
     # Find the first central info marker.
     for line in cmd.stdout:
       if self.zipinfo_central_directory_line.search(line):
@@ -284,6 +285,10 @@ class TraceConverter:
       if not file_name and offset >= start and offset < end:
         file_name = cur_name
 
+    # Make sure the offset_list is sorted, the zip file does not guarantee
+    # that the entries are in order.
+    offset_list = sorted(offset_list, key=lambda entry: entry[1])
+
     # Save the information from the zip.
     tmp_files = dict()
     self.apk_info[apk] = [apk_full_path, offset_list, tmp_files]