diff --git a/.github/workflows/validity-check.yml b/.github/workflows/validity-check.yml
index 7033be4..b6c9ca6 100644
--- a/.github/workflows/validity-check.yml
+++ b/.github/workflows/validity-check.yml
@@ -3,6 +3,8 @@ on:
   push:
     paths:
       - '**.csv'
+    branches:
+      - main
   pull_request:
     paths:
       - '**.csv'
diff --git a/tools/preflight-check.py b/tools/preflight-check.py
index 2975f69..8a8f728 100755
--- a/tools/preflight-check.py
+++ b/tools/preflight-check.py
@@ -1,12 +1,15 @@
 #!/usr/bin/env python3
 
 import sys
+import os
 import csv
 
 SUPPORTED_STORES = ["amazon", "battlenet", "none", "egs", "ubisoft", "ea", "humble", "itchio", "steam", "gog", "zoomplatform"]
 
 def main():
     file = sys.argv[1]
+    filename = os.path.basename(file)
+    has_error = False
     with open(file, 'r') as csvfile:
         rows = csv.reader(csvfile)
         header = True
@@ -17,8 +20,14 @@ def main():
                 continue
 
             if not row:
-                print("Empty row found:", i)
-                exit(1)
+                print(f"::error file={filename},line={i}::empty row found")
+                has_error = True
+                continue
+
+            if len(row) != 6:
+                print(f"::error file={filename},line={i}::incorrect number of columns")
+                has_error = True
+                continue
 
             title = row[0]
             store = row[1]
@@ -26,21 +35,26 @@ def main():
             umu_id = row[3]
 
             if not (title and store and codename and umu_id):
-                print("At least one of the required fields is missing, in row:", i)
-                exit(1)
+                print(f"::error file={filename},line={i}::At least one of the required fields is missing")
+                has_error = True
+                continue
 
             if store not in SUPPORTED_STORES:
-                print("Invalid store provided", store, "in row", i)
-                exit(1)
+                print(f"::error file={filename},line={i}::Invalid store provided '{store}'")
+                has_error = True
+                continue
 
             if store == "none" and codename == "none":
                 continue
             release_id = f"{store}_{codename}"
             if release_id in release_ids:
-                print("Duplicate entry found", title, store, codename, "in row", i)
-                exit(1)
+                print(f"::error file={filename},line={i}::Duplicate entry found '{title}, {store}, {codename}'")
+                has_error = True
+                continue
             release_ids.append(release_id)
-
+    
+    if has_error:
+        exit(1)
 
 if __name__ == "__main__":
     main()