diff --git a/src/api2/tape/drive.rs b/src/api2/tape/drive.rs
index 107bcfd8..2175a460 100644
--- a/src/api2/tape/drive.rs
+++ b/src/api2/tape/drive.rs
@@ -528,7 +528,7 @@ fn write_media_label(
             label.label_text,
             pool
         );
-        let set = MediaSetLabel::with_data(pool, [0u8; 16].into(), 0, label.ctime, None);
+        let set = MediaSetLabel::new_unassigned(pool, label.ctime);
 
         drive.write_media_set_label(&set, None)?;
 
@@ -575,7 +575,7 @@ fn write_media_label(
             if let Some(ref pool) = pool {
                 match info.media_set_label {
                     Some(set) => {
-                        if set.uuid != [0u8; 16].into() {
+                        if !set.unassigned() {
                             bail!("verify media set label failed - got wrong set uuid");
                         }
                         if &set.pool != pool {
@@ -1301,7 +1301,7 @@ pub fn catalog_media(
                     return Ok(());
                 }
                 Some(ref set) => {
-                    if set.uuid.as_ref() == [0u8; 16] {
+                    if set.unassigned() {
                         // media is empty
                         task_log!(worker, "media is empty");
                         let _lock = lock_unassigned_media_pool(TAPE_STATUS_DIR)?;
diff --git a/src/api2/tape/media.rs b/src/api2/tape/media.rs
index ed0105b0..cdeffd5b 100644
--- a/src/api2/tape/media.rs
+++ b/src/api2/tape/media.rs
@@ -336,8 +336,7 @@ pub fn destroy_media(label_text: String, force: Option<bool>) -> Result<(), Erro
 
     if !force {
         if let Some(ref set) = media_id.media_set_label {
-            let is_empty = set.uuid.as_ref() == [0u8; 16];
-            if !is_empty {
+            if !set.unassigned() {
                 bail!(
                     "media '{}' contains data (please use 'force' flag to remove.",
                     label_text
diff --git a/src/tape/file_formats/mod.rs b/src/tape/file_formats/mod.rs
index 2b7c9866..f80e2d90 100644
--- a/src/tape/file_formats/mod.rs
+++ b/src/tape/file_formats/mod.rs
@@ -168,4 +168,12 @@ impl MediaSetLabel {
             encryption_key_fingerprint,
         }
     }
+
+    pub fn new_unassigned(pool: &str, ctime: i64) -> Self {
+        Self::with_data(pool, [0u8; 16].into(), 0, ctime, None)
+    }
+
+    pub fn unassigned(&self) -> bool {
+        self.uuid.as_ref() == [0u8; 16]
+    }
 }
diff --git a/src/tape/inventory.rs b/src/tape/inventory.rs
index 9c5887d7..dd560179 100644
--- a/src/tape/inventory.rs
+++ b/src/tape/inventory.rs
@@ -185,7 +185,7 @@ impl Inventory {
             // do not overwrite unsaved pool assignments
             if media_id.media_set_label.is_none() {
                 if let Some(ref set) = previous.id.media_set_label {
-                    if set.uuid.as_ref() == [0u8; 16] {
+                    if set.unassigned() {
                         media_id.media_set_label = Some(set.clone());
                     }
                 }
@@ -251,15 +251,11 @@ impl Inventory {
     pub fn lookup_media_pool(&self, uuid: &Uuid) -> Option<(&str, bool)> {
         match self.map.get(uuid) {
             None => None,
-            Some(entry) => {
-                match entry.id.media_set_label {
-                    None => None, // not assigned to any pool
-                    Some(ref set) => {
-                        let is_empty = set.uuid.as_ref() == [0u8; 16];
-                        Some((&set.pool, is_empty))
-                    }
-                }
-            }
+            Some(entry) => entry
+                .id
+                .media_set_label
+                .as_ref()
+                .map(|set| (set.pool.as_str(), set.unassigned())),
         }
     }
 
@@ -275,7 +271,7 @@ impl Inventory {
                         continue; // belong to another pool
                     }
 
-                    if set.uuid.as_ref() == [0u8; 16] {
+                    if set.unassigned() {
                         list.push(MediaId {
                             label: entry.id.label.clone(),
                             media_set_label: None,
@@ -298,7 +294,7 @@ impl Inventory {
             match entry.id.media_set_label {
                 None => continue, // not assigned to any pool
                 Some(ref set) => {
-                    if set.uuid.as_ref() != [0u8; 16] {
+                    if set.unassigned() {
                         list.push(entry.id.clone());
                     }
                 }
@@ -410,7 +406,7 @@ impl Inventory {
             .map
             .values()
             .filter_map(|entry| entry.id.media_set_label.as_ref())
-            .filter(|set| set.pool == pool && set.uuid.as_ref() != [0u8; 16]);
+            .filter(|set| set.pool == pool && !set.unassigned());
 
         for set in set_list {
             match last_set {
@@ -435,7 +431,7 @@ impl Inventory {
             .map
             .values()
             .filter_map(|entry| entry.id.media_set_label.as_ref())
-            .filter(|set| set.pool == pool && set.uuid.as_ref() != [0u8; 16]);
+            .filter(|set| set.pool == pool && !set.unassigned());
 
         for set in set_list {
             if set.uuid != uuid && set.ctime >= ctime {
@@ -600,7 +596,7 @@ impl Inventory {
 
         let uuid = label.uuid.clone();
 
-        let set = MediaSetLabel::with_data(pool, [0u8; 16].into(), 0, ctime, None);
+        let set = MediaSetLabel::new_unassigned(pool, ctime);
 
         self.store(
             MediaId {
diff --git a/src/tape/media_pool.rs b/src/tape/media_pool.rs
index eb477885..e1bba9ab 100644
--- a/src/tape/media_pool.rs
+++ b/src/tape/media_pool.rs
@@ -181,7 +181,7 @@ impl MediaPool {
             // should never trigger
             return (MediaStatus::Unknown, location); // belong to another pool
         }
-        if set.uuid.as_ref() == [0u8; 16] {
+        if set.unassigned() {
             // not assigned to any pool
             return (MediaStatus::Writable, location);
         }