diff --git a/src/generate_images.py b/src/generate_images.py
index 5a18ce6..8926477 100644
--- a/src/generate_images.py
+++ b/src/generate_images.py
@@ -61,12 +61,12 @@ def crop_image(file):
 
 def generate_concat(images, dest):
     if os.path.exists(dest):
-        if input("Overwrite {dest} ? [y/N] ").lower() != "y":
+        if input(f"Overwrite {dest} ? [y/N] ").lower() != "y":
             return
 
     content = "ffconcat version 1.0"
     for img in images:
-        content += "\nfile {img}\nduration 8"
+        content += f"\nfile {img}\nduration 8"
 
     with open(dest, "w") as f:
         f.write(content)