diff --git a/pom.xml b/pom.xml
index 8fc0eaa3..4044fa37 100644
--- a/pom.xml
+++ b/pom.xml
@@ -149,7 +149,7 @@
     <dependency>
       <groupId>com.twelvemonkeys.imageio</groupId>
       <artifactId>imageio-tiff</artifactId>
-      <version>3.9.4</version>
+      <version>3.10.1</version>
     </dependency>
     <dependency>
       <groupId>de.digitalcollections.commons</groupId>
diff --git a/src/main/java/de/digitalcollections/iiif/hymir/image/business/ImageServiceImpl.java b/src/main/java/de/digitalcollections/iiif/hymir/image/business/ImageServiceImpl.java
index be403414..5f2b6d4a 100644
--- a/src/main/java/de/digitalcollections/iiif/hymir/image/business/ImageServiceImpl.java
+++ b/src/main/java/de/digitalcollections/iiif/hymir/image/business/ImageServiceImpl.java
@@ -348,7 +348,7 @@ private DecodedImage readImage(
     }
   }
 
-  /** Apply transformations to an decoded image * */
+  /** Apply transformations to a decoded image * */
   private BufferedImage transformImage(
       BufferedImage inputImage,
       Dimension targetSize,
@@ -403,7 +403,7 @@ private BufferedImage transformImage(
         outType = BufferedImage.TYPE_3BYTE_BGR;
         break;
       default:
-        outType = inType;
+        outType = inType == BufferedImage.TYPE_CUSTOM ? BufferedImage.TYPE_3BYTE_BGR : inType;
     }
     if (outType != img.getType()) {
       BufferedImage newImg = new BufferedImage(img.getWidth(), img.getHeight(), outType);