diff --git a/src/modes/update.rs b/src/modes/update.rs
index 671fc9e..c924b1f 100644
--- a/src/modes/update.rs
+++ b/src/modes/update.rs
@@ -66,12 +66,13 @@ pub fn mode_update(
     }
 
     // If digest is defined and not None, but digest_value is missing, recalculate it
-    if item.digest_type != "None" && item.digest_value.is_none() {
-        debug!("MAIN: Recalculating digest for item {:?}", item.id);
-        
-        // Get the digest type
-        let digest_type = DigestType::from_str(&item.digest_type)?;
-        let mut digest_engine = get_digest_engine(digest_type);
+    if let Some(digest_type_str) = item.digest_type.as_ref() {
+        if digest_type_str != "None" && item.digest_value.is_none() {
+            debug!("MAIN: Recalculating digest for item {:?}", item.id);
+            
+            // Get the digest type
+            let digest_type = DigestType::from_str(digest_type_str)?;
+            let mut digest_engine = get_digest_engine(digest_type);
         
         // Read the file using the compression engine
         let compression_type = CompressionType::from_str(&item.compression)?;