diff --git a/README.md b/README.md
index c2dfad9..68e2f88 100644
--- a/README.md
+++ b/README.md
@@ -4,9 +4,7 @@ ISIN Data from various public securities.
 
 Source: [NSDL Website Detailed ISIN Search][nsdl].
 
-Automatically updated every Sunday using GitHub Actions.
-
-Currently tracked:
+Automatically updated every midnight (IST).
 
 |File|Issuer|Tracked|
 -----|-----|----|
@@ -26,6 +24,7 @@ You can run the `fetch.sh` script to generate the tracked the files from scratch
 - https://stedolan.github.io/jq/
 - https://www.gnu.org/software/parallel/
 - https://curl.se/
+- https://www.gnu.org/software/sed/
 
 # Structure
 
diff --git a/fetch.sh b/fetch.sh
index 19174d0..ea307b5 100755
--- a/fetch.sh
+++ b/fetch.sh
@@ -59,4 +59,7 @@ sem --wait
 for i in E F 9; do
   # Sort the file in place
   sort -o "IN$i.csv" "IN$i.csv"
+  # Remove lines that don't start with the correct prefix
+  # This is to avoid ISINs like INF955L01IN9 showing up under IN9
+  sed -i '/^IN$i/!d' "IN$i.csv"
 done
\ No newline at end of file