diff --git a/.github/workflows/language-check.yml b/.github/workflows/language-check.yml
index 7fe05e09..a5134399 100644
--- a/.github/workflows/language-check.yml
+++ b/.github/workflows/language-check.yml
@@ -27,7 +27,8 @@ jobs:
         # Scrape ISO 639 language codes from the Wiki page
         wget -qO- https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes | \
         nokogiri -e 'puts $_.css(".wikitable td:nth-child(2)").map(&:text)' | \
-        sed -nr '/^.{0,2}$/p' > iso639.txt  # Grab only two letter values
+        sed -nr '/^.{0,2}$/p' |  # Grab only two letter values
+        tr '[:lower:]' '[:upper:]' > iso639.txt # Covert letters to uppercase
 
         # Get list of README file names
         readme_suffixes=$(ls README-* | sed 's/README-//g; s/.md//g')