diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index 1a9733da9a..3646c2b9fc 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -261,8 +261,9 @@ class Event(object):
                                           self.name,
                                           self.args,
                                           fmt)
-
-    _FMT = re.compile("(%[\d\.]*\w+|%.*PRI\S+)")
+    # Star matching on PRI is dangerous as one might have multiple
+    # arguments with that format, hence the non-greedy version of it.
+    _FMT = re.compile("(%[\d\.]*\w+|%.*?PRI\S+)")
 
     def formats(self):
         """List conversion specifiers in the argument print format string."""