diff --git a/.travis.yml b/.travis.yml
index 6fb2d61..f6a1b05 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,3 @@
-language: c
-install:
-    - sudo apt-get update -qq
-    - sudo apt-get install -q vim-common file libffi6 libgmp10
-    - curl -L "http://archive.ubuntu.com/ubuntu/pool/universe/s/shellcheck/shellcheck_0.4.6-1_amd64.deb" -o "/tmp/shellcheck_0.4.6-1_amd64.deb"
-    - '[ "$(openssl dgst -sha256 "/tmp/shellcheck_0.4.6-1_amd64.deb" | cut -d " " -f 2)" == "95b4d2577f25ae47918bd53068a5ff42d5c34e5f884daa8dae32253044b45370" ]'
-    - sudo dpkg -i "/tmp/shellcheck_0.4.6-1_amd64.deb"
+language: shell
+dist: bionic
 script: make && make test SHELL="bash -x"
diff --git a/google-font-download b/google-font-download
index 73edda5..8e54160 100755
--- a/google-font-download
+++ b/google-font-download
@@ -349,6 +349,7 @@ if [ "$(echo "test" | sed -E 's/([st]+)$/xx\1/' 2>/dev/null)" == "texxst" ]; the
 elif [ "$(echo "test" | sed -r 's/([st]+)$/xx\1/' 2>/dev/null)" == "texxst" ]; then
 	ESED="sed -r"
 else
+	# shellcheck disable=SC2230
 	err_exit "$(which sed) seems to lack extended regex support with -E or -r"
 fi
 
@@ -431,7 +432,7 @@ for family in "${families[@]}"; do
 	# For each requested font format, download the font file and print the corresponding CSS statements.
 	for ((uaidx=0; uaidx < ${#formats[@]}; uaidx++)); do
 		uakey=${formats[$uaidx]}
-		if [ $uaidx -eq $(( ${#formats[@]} - 1 )) ]; then
+		if [ "$uaidx" -eq $(( ${#formats[@]} - 1 )) ]; then
 			terminator=";"
 		else
 			terminator=","