diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 68d0757c..839f9449 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -58,7 +58,7 @@ jobs:
     - name: Byte compilation
       run: emacs --eval "(setq byte-compile-error-on-warn (>= emacs-major-version 26))" -L . --batch -f batch-byte-compile ./*.el
     - name: Tests
-      run: nix shell ${{ matrix.ledger_version || 'nixpkgs#ledger' }} --print-build-logs -c ./makem.sh test -vv
+      run: nix shell 'nixpkgs#getopt' ${{ matrix.ledger_version || 'nixpkgs#ledger' }} --print-build-logs -c ./makem.sh test -vv
     # This is currently for information only, since a lot of docstrings need fixing up
     - name: Checkdoc
       run: make lint-checkdoc || true
diff --git a/makem.sh b/makem.sh
index fd81e0f8..cb8d6bd2 100755
--- a/makem.sh
+++ b/makem.sh
@@ -406,7 +406,7 @@ function files-project {
     # matching that pattern with "git ls-files".  Excludes submodules.
     [[ $1 ]] && pattern="/$1" || pattern="."
 
-    local excludes
+    local excludes=()
     for submodule in $(submodules)
     do
         excludes+=(":!:$submodule")
@@ -424,7 +424,7 @@ function dirs-project {
 function files-project-elisp {
     # Echo list of Elisp files in project.
     files-project 2>/dev/null \
-        | egrep "\.el$" \
+        | grep -E "\.el$" \
         | filter-files-exclude-default \
         | filter-files-exclude-args
 }