diff --git a/ttfb b/ttfb
index 0f9e49c..e5a84c9 100755
--- a/ttfb
+++ b/ttfb
@@ -65,6 +65,14 @@ for dependency in curl bc column; do
   which -s $dependency || (echo "You need to have '$dependency' installed and in your \$PATH" >&2 && exit 1)
 done
 
+# Ensure curl uses period separators for floating point values, which
+# bc requires to do calculations (i.e. it can't use locale separators like ,)
+if (locale -a | egrep ^C.UTF-8$); then
+  export LC_ALL=C.UTF-8
+else
+  export LC_ALL=C
+fi
+
 # Cribbed from https://stackoverflow.com/a/41762669/391826
 median() {
   arr=($(printf '%s\n' "${@}" | sort -n))