diff --git a/src/ImageSharp.Web.Providers.AWS/AmazonS3ClientFactory.cs b/src/ImageSharp.Web.Providers.AWS/AmazonS3ClientFactory.cs
index d3589384..624963d9 100644
--- a/src/ImageSharp.Web.Providers.AWS/AmazonS3ClientFactory.cs
+++ b/src/ImageSharp.Web.Providers.AWS/AmazonS3ClientFactory.cs
@@ -9,6 +9,8 @@ namespace SixLabors.ImageSharp.Web;
 
 internal static class AmazonS3ClientFactory
 {
+    static AmazonS3ClientFactory() => AWSConfigs.InitializeCollections = true;
+
     /// <summary>
     /// Creates a new bucket under the specified account if a bucket
     /// with the same name does not already exist.
diff --git a/src/ImageSharp.Web.Providers.AWS/ImageSharp.Web.Providers.AWS.csproj b/src/ImageSharp.Web.Providers.AWS/ImageSharp.Web.Providers.AWS.csproj
index a899bc38..b6c531d7 100644
--- a/src/ImageSharp.Web.Providers.AWS/ImageSharp.Web.Providers.AWS.csproj
+++ b/src/ImageSharp.Web.Providers.AWS/ImageSharp.Web.Providers.AWS.csproj
@@ -43,7 +43,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="AWSSDK.S3" Version="3.7.103.42" />
+    <PackageReference Include="AWSSDK.S3" Version="4.0.1.2" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/ImageSharp.Web.Providers.AWS/Resolvers/AWSS3StorageImageResolver.cs b/src/ImageSharp.Web.Providers.AWS/Resolvers/AWSS3StorageImageResolver.cs
index dd7c2b4e..483269c1 100644
--- a/src/ImageSharp.Web.Providers.AWS/Resolvers/AWSS3StorageImageResolver.cs
+++ b/src/ImageSharp.Web.Providers.AWS/Resolvers/AWSS3StorageImageResolver.cs
@@ -49,7 +49,7 @@ public async Task<ImageMetadata> GetMetaDataAsync()
             }
         }
 
-        return new ImageMetadata(metadata.LastModified, maxAge, metadata.ContentLength);
+        return new ImageMetadata(metadata.LastModified ?? DateTime.UtcNow, maxAge, metadata.ContentLength);
     }
 
     /// <inheritdoc />