1 files changed, 1 insertions, 1 deletions

diff --git a/unit_trace/trace_reader.py b/unit_trace/trace_reader.py
index 60450a6..e7b8630 100644
--- a/unit_trace/trace_reader.py
+++ b/unit_trace/trace_reader.py
@@ -204,7 +204,7 @@ class StHeader:
     message = 'The header.'
 
 class StActionData:
-    format =  'QH'
+    format =  'QI'
     formatStr = struct.Struct(StHeader.format + format)
     keys = StHeader.keys + ['when','action']
     message = 'An action was performed.'