diff --git a/app.py b/app.py
index 2cb7fe0..4bc9a9e 100644
--- a/app.py
+++ b/app.py
@@ -56,7 +56,17 @@ class User(Base):
     is_admin = Column(Boolean, default=False)  # Admin flag
 
 
-import uuid  # Add this import at the top of your file
+def get_mime_type(extension):
+    extension = extension.lower()
+    if extension == 'jpg' or extension == 'jpeg':
+        return 'image/jpeg'
+    elif extension == 'png':
+        return 'image/png'
+    elif extension == 'gif':
+        return 'image/gif'
+    else:
+        return 'application/octet-stream'
+
 
 class Puzzle(Base):
     __tablename__ = "puzzles"
@@ -64,6 +74,7 @@ class Puzzle(Base):
     date = Column(Date, nullable=False)
     size = Column(Integer, nullable=False)  # 3, 4, or 5
     image_b64 = Column(String, nullable=False)
+    image_extension = Column(String, nullable=False)
 
     # Remove the nullable=False constraint as we'll generate these after creation
     initial_state_json = Column(String)
@@ -72,16 +83,25 @@ class Puzzle(Base):
     title = Column(String, default="Daily Puzzle")
     is_visible = Column(Boolean, default=True)
 
-    def __init__(self, date, size, image_b64, title="Daily Puzzle", is_visible=True):
+    def __init__(self, date, size, image_b64, image_extension, title="Daily Puzzle", is_visible=True):
         self.date = date
         self.size = size
         self.image_b64 = image_b64
+        self.image_extension = image_extension
         self.title = title
         self.is_visible = is_visible
 
         # Generate initial and solution states
         self.generate_states()
 
+    @property
+    def filename_slug(self):
+        return f"{slugify(self.title)}.{self.image_extension}"
+
+    @property
+    def image_mime_type(self):
+        return get_mime_type(self.image_extension)
+
     def generate_states(self):
         total_pieces = self.size * self.size
         pieces = []
@@ -646,10 +666,10 @@ def upload_post_view(request):
 
         # Validate file type
         allowed_extensions = {"png", "jpg", "jpeg", "gif"}
-        if not any(
-            image_file.filename.lower().endswith(f".{ext}")
-            for ext in allowed_extensions
-        ):
+        filename = image_file.filename.lower()
+        file_extension = os.path.splitext(filename)[1][1:]  # Get extension without dot
+
+        if file_extension not in allowed_extensions:
             return Response(
                 f"Unsupported file type for {size}x{size} puzzle. Allowed types: png, jpg, jpeg, gif.",
                 status=400,
@@ -676,6 +696,7 @@ def upload_post_view(request):
             date=puzzle_date,
             size=size,
             image_b64=encoded_str,
+            image_extension=file_extension,  # Pass the file extension here
             title=title,
         )
         s.add(puzzle)
@@ -763,9 +784,6 @@ def daily_puzzle_view(request):
             attempt.state_json = existing_solve.state_json
             s.commit()
 
-    # Prepare the puzzle filename for the download button
-    puzzle_filename = slugify(puzzle.title) + ".png"
-
     # Get user's rank if they have solved it
     user_rank = None
     if existing_solve:
@@ -786,8 +804,6 @@ def daily_puzzle_view(request):
                 user_rank = idx + 1
                 break
 
-
-
     return {
         "request": request,
         "puzzle": puzzle,
@@ -797,6 +813,7 @@ def daily_puzzle_view(request):
         "rotation_count": attempt.rotation_count,
         "attempt_is_solved": attempt.is_solved or existing_solve is not None,
         "user_rank": user_rank,
+        "image_mime_type": puzzle.image_mime_type,
     }
 
 
diff --git a/templates/daily_puzzle.html.j2 b/templates/daily_puzzle.html.j2
index 0caf906..1178ecc 100644
--- a/templates/daily_puzzle.html.j2
+++ b/templates/daily_puzzle.html.j2
@@ -364,7 +364,7 @@ document.addEventListener("DOMContentLoaded", function() {
     function downloadImage() {
         const link = document.createElement('a');
         link.href = 'data:image/png;base64,{{ puzzle.image_b64 }}';
-        link.download = "{{ puzzle.filename }}";
+        link.download = "{{ puzzle.filename_slug }}";
         document.body.appendChild(link);
         link.click();
         document.body.removeChild(link);