diff --git a/test/shimexec/fish b/test/shimexec/fish
index c7d2331..cd5574c 100755
--- a/test/shimexec/fish
+++ b/test/shimexec/fish
@@ -4,7 +4,7 @@ HERE="$(cd "$(dirname "$0")" && pwd)"
 while read -d ':' -r dir; do
 	if [[ "$dir" == "$HERE" || -z "$dir" ]]; then continue; fi
 	if [[ -f "${dir}/fish" ]]; then
-		TMPDIR= "${dir}/fish" "$@"
+		TMPDIR='' "${dir}/fish" "$@"
 		exit $?
 	fi
 done <<<"$PATH:"
diff --git a/test/suite/batpipe.sh b/test/suite/batpipe.sh
index f16509f..c4b7164 100644
--- a/test/suite/batpipe.sh
+++ b/test/suite/batpipe.sh
@@ -13,6 +13,7 @@ test:detected_bash_shell() {
 test:detected_fish_shell() {
 	description "Test it can detect a bash shell."
 	command -v "fish" &>/dev/null || skip "Test requires fish shell."
+	fish -c 'exit 0' &>/dev/null || skip "Test requires fish shell." # This is in case it finds "fish" in shimexec dir.
 	
 	output="$(SHELL="fish" fish --login -c "$(batpipe_path)")"
 	grep '^set -x' <<< "$output" >/dev/null || fail "Detected the wrong shell for fish."