diff --git a/Iceshrimp.Backend/Core/Services/DriveService.cs b/Iceshrimp.Backend/Core/Services/DriveService.cs
index 5fbb3665..8ccd0444 100644
--- a/Iceshrimp.Backend/Core/Services/DriveService.cs
+++ b/Iceshrimp.Backend/Core/Services/DriveService.cs
@@ -216,7 +216,7 @@ public class DriveService(
 				else
 				{
 					data.Seek(0, SeekOrigin.Begin);
-					await storageSvc.UploadFileAsync(filename, data);
+					await storageSvc.UploadFileAsync(filename, request.MimeType, data);
 					url = storageSvc.GetFilePublicUrl(filename).AbsoluteUri;
 
 					if (thumbnailFilename != null && res?.RenderThumbnail != null)
@@ -226,7 +226,7 @@ public class DriveService(
 							await using var stream = new MemoryStream();
 							await res.RenderThumbnail(stream);
 							stream.Seek(0, SeekOrigin.Begin);
-							await storageSvc.UploadFileAsync(thumbnailFilename, stream);
+							await storageSvc.UploadFileAsync(thumbnailFilename, "image/webp", stream);
 							thumbnailUrl = storageSvc.GetFilePublicUrl(thumbnailFilename).AbsoluteUri;
 						}
 						catch (Exception e)
@@ -242,7 +242,7 @@ public class DriveService(
 							await using var stream = new MemoryStream();
 							await res.RenderWebpublic(stream);
 							stream.Seek(0, SeekOrigin.Begin);
-							await storageSvc.UploadFileAsync(webpublicFilename, stream);
+							await storageSvc.UploadFileAsync(webpublicFilename, "image/webp", stream);
 							webpublicUrl = storageSvc.GetFilePublicUrl(webpublicFilename).AbsoluteUri;
 						}
 						catch (Exception e)
@@ -267,7 +267,7 @@ public class DriveService(
 				else
 				{
 					data.Seek(0, SeekOrigin.Begin);
-					await storageSvc.UploadFileAsync(filename, data);
+					await storageSvc.UploadFileAsync(filename, request.MimeType, data);
 					url = storageSvc.GetFilePublicUrl(filename).AbsoluteUri;
 				}
 			}
diff --git a/Iceshrimp.Backend/Core/Services/ObjectStorageService.cs b/Iceshrimp.Backend/Core/Services/ObjectStorageService.cs
index 53d2f320..4031781b 100644
--- a/Iceshrimp.Backend/Core/Services/ObjectStorageService.cs
+++ b/Iceshrimp.Backend/Core/Services/ObjectStorageService.cs
@@ -61,7 +61,7 @@ public class ObjectStorageService(IOptions<Config.StorageSection> config, HttpCl
 		const string filename = ".iceshrimp-test";
 		var          content  = CryptographyHelpers.GenerateRandomString(16);
 
-		await UploadFileAsync(filename, Encoding.UTF8.GetBytes(content));
+		await UploadFileAsync(filename, "text/plain", Encoding.UTF8.GetBytes(content));
 
 		string result;
 		try
@@ -78,12 +78,15 @@ public class ObjectStorageService(IOptions<Config.StorageSection> config, HttpCl
 		throw new Exception("Failed to verify access url (content mismatch)");
 	}
 
-	private Task UploadFileAsync(string filename, byte[] data) => UploadFileAsync(filename, new MemoryStream(data));
+	private Task UploadFileAsync(string filename, string contentType, byte[] data) =>
+		UploadFileAsync(filename, contentType, new MemoryStream(data));
 
-	public async Task UploadFileAsync(string filename, Stream data)
+	public async Task UploadFileAsync(string filename, string contentType, Stream data)
 	{
 		if (_bucket == null) throw new Exception("Refusing to upload to object storage with invalid configuration");
-		var blob = new Blob(GetFilenameWithPrefix(filename), data, _acl ?? BlobProperties.Empty);
+		var properties = (_acl ?? BlobProperties.Empty).ToDictionary();
+		properties.Add("Content-Type", contentType);
+		var blob = new Blob(GetFilenameWithPrefix(filename), data, properties);
 		await _bucket.PutAsync(blob);
 	}
 
diff --git a/Iceshrimp.Backend/Core/Services/StorageMaintenanceService.cs b/Iceshrimp.Backend/Core/Services/StorageMaintenanceService.cs
index 8c77b380..c0c9ac13 100644
--- a/Iceshrimp.Backend/Core/Services/StorageMaintenanceService.cs
+++ b/Iceshrimp.Backend/Core/Services/StorageMaintenanceService.cs
@@ -55,7 +55,7 @@ public class StorageMaintenanceService(
 				var path   = Path.Join(pathBase, file.AccessKey);
 				var stream = File.OpenRead(path);
 
-				await objectStorageSvc.UploadFileAsync(file.AccessKey, stream);
+				await objectStorageSvc.UploadFileAsync(file.AccessKey, file.Type, stream);
 				file.Url = objectStorageSvc.GetFilePublicUrl(file.AccessKey).AbsoluteUri;
 				pathsToDelete.Add(path);
 			}
@@ -65,7 +65,7 @@ public class StorageMaintenanceService(
 				var path   = Path.Join(pathBase, file.ThumbnailAccessKey);
 				var stream = File.OpenRead(path);
 
-				await objectStorageSvc.UploadFileAsync(file.ThumbnailAccessKey, stream);
+				await objectStorageSvc.UploadFileAsync(file.ThumbnailAccessKey, "image/webp", stream);
 				file.ThumbnailUrl = objectStorageSvc.GetFilePublicUrl(file.ThumbnailAccessKey).AbsoluteUri;
 				pathsToDelete.Add(path);
 			}
@@ -75,7 +75,7 @@ public class StorageMaintenanceService(
 				var path   = Path.Join(pathBase, file.WebpublicAccessKey);
 				var stream = File.OpenRead(path);
 
-				await objectStorageSvc.UploadFileAsync(file.WebpublicAccessKey, stream);
+				await objectStorageSvc.UploadFileAsync(file.WebpublicAccessKey, "image/webp", stream);
 				file.WebpublicUrl = objectStorageSvc.GetFilePublicUrl(file.WebpublicAccessKey).AbsoluteUri;
 				pathsToDelete.Add(path);
 			}