diff --git a/flake.nix b/flake.nix
index 80ea68b..5115f03 100644
--- a/flake.nix
+++ b/flake.nix
@@ -55,19 +55,21 @@
       packages.${system} = {
         ${name} = oms; # nixpkgs.legacyPackages.${system}.${name};
         mkOauth2DB = pkgs.writeScriptBin "mkOauth2DB" ''
-          #!${pkgs.zsh}/bis/zsh -e
+          #!${pkgs.zsh}/bin/zsh -e
           ${mkDB}
         '';
         killOauth2DB = pkgs.writeScriptBin "killOauth2DB" ''
-          #!${pkgs.zsh}/bis/zsh -e
+          #!${pkgs.zsh}/bin/zsh -e
           ${killDB}
         '';
         default = self.packages.${system}.${name};
       };
 
       devShells.${system}.default = pkgs.mkShell {
-        buildInputs = buildInputs;
+        buildInputs = buildInputs ++ (with self.packages.${system}; [mkOauth2DB killOauth2DB]);
         LD_LIBRARY_PATH = libPath;
+        OAUTH2_HBA = ./hba_file;
+        OAUTH2_DB_SCHEMA = ./schema.sql;
         shellHook = ''
           ${mkDB}
           zsh
diff --git a/mkDB.sh b/mkDB.sh
index bd444ec..16330e4 100755
--- a/mkDB.sh
+++ b/mkDB.sh
@@ -3,6 +3,8 @@
 #
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
+[[ -z "${OAUTH2_HBA}" || -z "${OAUTH2_DB_SCHEMA}" ]] && echo "oauth2: missing env vars for hba and/or schema" && exit 1
+
 export OAUTH2_SERVER_PORT=9443
 export OAUTH2_DB_PORT=9444
 
@@ -19,8 +21,8 @@ pgSockDir=$(mktemp -d --tmpdir="${absdir}" postgresql.sock.XXXXXX)
 pgLogFile=$(mktemp --tmpdir="${absdir}" postgresql.XXXXXX.log)
 
 initdb --no-locale -D "${pgDir}"
-pg_ctl start -D "${pgDir}" -l "${pgLogFile}" -w -o "-k ${pgSockDir} -c listen_addresses='::' -c hba_file='hba_file' -p ${OAUTH2_DB_PORT} -h localhost -c unix_socket_permissions=0700 -c max_connections=10 -c session_preload_libraries=auto_explain -c auto_explain.log_min_duration=100ms"
-psql -h "${pgSockDir}" -p ${OAUTH2_DB_PORT} -f ./schema.sql postgres
+pg_ctl start -D "${pgDir}" -l "${pgLogFile}" -w -o "-k ${pgSockDir} -c listen_addresses='::' -c hba_file='${OAUTH2_HBA}' -p ${OAUTH2_DB_PORT} -h localhost -c unix_socket_permissions=0700 -c max_connections=10 -c session_preload_libraries=auto_explain -c auto_explain.log_min_duration=100ms"
+psql -h "${pgSockDir}" -p ${OAUTH2_DB_PORT} -f ${OAUTH2_DB_SCHEMA} postgres
 
 printf "Postgres logfile is %s\nPostgres socket directory is %s\n" "${pgLogFile}" "${pgSockDir}"