diff --git a/pkgs/by-name/wp/wp-cli/package.nix b/pkgs/by-name/wp/wp-cli/package.nix
index 40b16ff60763..f0bb1e9ee7b7 100644
--- a/pkgs/by-name/wp/wp-cli/package.nix
+++ b/pkgs/by-name/wp/wp-cli/package.nix
@@ -42,6 +42,9 @@ stdenv.mkDerivation (finalAttrs: {
 
   nativeBuildInputs = [ installShellFiles makeWrapper ];
 
+  # Usually --set-default is used to set default environment variables.
+  # But the value is wrapped in single-quotes so our variables would be used literally instead
+  # of the expanded version. Thus we use --run instead.
   installPhase = ''
     runHook preInstall
 
@@ -50,12 +53,12 @@ stdenv.mkDerivation (finalAttrs: {
     installShellCompletion --bash --name wp ${completion}
 
     makeWrapper ${lib.getExe php} $out/bin/${finalAttrs.meta.mainProgram} \
-      --set-default XDG_CACHE_HOME \$HOME/.cache \
-      --set-default XDG_CONFIG_HOME \$HOME/.config \
-      --set-default XDG_DATA_HOME \$HOME/.local/share \
-      --set-default WP_CLI_CONFIG_PATH \$XDG_CONFIG_HOME}/wp-cli \
-      --set-default WP_CLI_PACKAGES_DIR \$XDG_DATA_HOME/wp-cli \
-      --set-default WP_CLI_CACHE_DIR \$XDG_CACHE_HOME/wp-cli \
+      --run 'export XDG_CACHE_HOME=''${XDG_CACHE_HOME-"$HOME/.cache"}' \
+      --run 'export XDG_CONFIG_HOME=''${XDG_CONFIG_HOME-"$HOME/.config"}' \
+      --run 'export XDG_DATA_HOME=''${XDG_DATA_HOME-"$HOME/.local/share"}' \
+      --run 'export WP_CLI_CONFIG_PATH=''${WP_CLI_CONFIG_PATH-"$XDG_CONFIG_HOME/wp-cli"}' \
+      --run 'export WP_CLI_PACKAGES_DIR=''${WP_CLI_PACKAGES_DIR-"$XDG_DATA_HOME/wp-cli"}' \
+      --run 'export WP_CLI_CACHE_DIR=''${WP_CLI_CACHE_DIR-"$XDG_CACHE_HOME/wp-cli"}' \
       --add-flags "-c $out/etc/${ini.name}" \
       --add-flags "-f $out/share/wp-cli/wp-cli.phar" \
       --add-flags "--"