diff --git a/models/Example31_Petri_Net.mp b/models/Example31_Petri_Net.mp
index d5aaaf51d14eec4c8a3fbf13911f690212b2f235..200d5faff8b59ada4f79e45cd7bd63bc05f728d4 100644
--- a/models/Example31_Petri_Net.mp
+++ b/models/Example31_Petri_Net.mp
@@ -1,4 +1,4 @@
-/* Example 32. Model of Petri Net
+/* Example 31. Model of Petri Net
 
 Purpose: To demonstrate the modeling of a Petri net in MP.