diff --git a/.drone.yml b/.drone.yml
index c129685..5b1871e 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -12,12 +12,11 @@ steps:
   - name: generate-ogp-images
     image: reg.kazu634.com/kazu634/tcardgen:v0.3
     commands:
-      - mkdir -p static/ogp/
       - wget 'https://github.com/yuru7/HackGen/releases/download/v2.3.0/HackGenNerd_v2.3.0.zip' -O /tmp/font.zip
       - unzip /tmp/font.zip -d /tmp/font
       - find /tmp/font -type f -name *.ttf | xargs -I% -n 1 cp -p % assets/font/
-      - find content/ -type f -name '*.md' | grep -v '_index' | xargs -n 1 /usr/local/bin/tcardgen -f assets/font/ -o static/ogp/ -c assets/tcardgen.yaml > /dev/null 2>&1
-      - find static/ogp/ -type f -name '*.png' | xargs -I% -n 1 img2webp -lossy -q 50 % -o `echo % | sed -e 's/png/webp/g'` > /dev/null 2>&1
+      - find content/ -type f -name '*.md' | grep -v '_index' | xargs -n 1 /usr/local/bin/tcardgen -f assets/font/ -o static/ogp/ -c assets/tcardgen.yaml > /dev/null
+      - find static/ogp/ -type f -name '*.png' | xargs -n 1 -I% basename % .png | xargs -I% -n 1 img2webp -lossy -q 50 static/ogp/%.png -o static/ogp/%.webp > /dev/null
       - find static/ogp/ -type f -name '*.png' | xargs --no-run-if-empty rm
 
   - name: hugo
diff --git a/static/ogp/.gitkeep b/static/ogp/.gitkeep
new file mode 100644
index 0000000..e69de29