diff --git a/src/backend/cache.rs b/src/backend/cache.rs
index a57a850..8d775d6 100644
--- a/src/backend/cache.rs
+++ b/src/backend/cache.rs
@@ -211,7 +211,7 @@ impl Cache {
             &offset
         );
         let mut file = File::open(self.path(tpe, id))?;
-        file.seek(SeekFrom::Start(offset as u64))?;
+        file.seek(SeekFrom::Start(u64::from(offset)))?;
         let mut vec = vec![0; length as usize];
         file.read_exact(&mut vec)?;
         trace!("cache hit!");
diff --git a/src/blob/packer.rs b/src/blob/packer.rs
index 4d95b77..09bef48 100644
--- a/src/blob/packer.rs
+++ b/src/blob/packer.rs
@@ -57,12 +57,14 @@ impl PackSizer {
     pub fn size_ok(&self, size: u32) -> bool {
         let target_size = self.pack_size();
         // Note: we cast to u64 so that no overflow can occur in the multiplications
-        size as u64 * 100 >= target_size as u64 * self.min_packsize_tolerate_percent as u64
-            && size as u64 * 100 <= target_size as u64 * self.max_packsize_tolerate_percent as u64
+        u64::from(size) * 100
+            >= u64::from(target_size) * u64::from(self.min_packsize_tolerate_percent)
+            && u64::from(size) * 100
+                <= u64::from(target_size) * u64::from(self.max_packsize_tolerate_percent)
     }
 
     fn add_size(&mut self, added: u32) {
-        self.current_size += added as u64;
+        self.current_size += u64::from(added);
     }
 }
 
@@ -135,7 +137,13 @@ impl<BE: DecryptWriteBackend> Packer<BE> {
                 NonZeroU32::new(data_len),
             ),
         };
-        self.add_raw(&data, id, data_len as u64, uncompressed_length, size_limit)
+        self.add_raw(
+            &data,
+            id,
+            u64::from(data_len),
+            uncompressed_length,
+            size_limit,
+        )
     }
 
     /// adds the already encrypted (and maybe compressed) blob to the packfile
diff --git a/src/commands/check.rs b/src/commands/check.rs
index eb40fb5..f463260 100644
--- a/src/commands/check.rs
+++ b/src/commands/check.rs
@@ -143,7 +143,7 @@ fn check_cache_files(
         return Ok(());
     }
 
-    let total_size = files.values().map(|size| *size as u64).sum();
+    let total_size = files.values().map(|size| u64::from(*size)).sum();
     p.set_length(total_size);
 
     files
@@ -168,7 +168,7 @@ fn check_cache_files(
                 (Ok(_), Ok(_)) => {} // everything ok
             }
 
-            p.inc(size as u64);
+            p.inc(u64::from(size));
         });
 
     p.finish();
diff --git a/src/commands/prune.rs b/src/commands/prune.rs
index 6049612..e0e810d 100644
--- a/src/commands/prune.rs
+++ b/src/commands/prune.rs
@@ -311,41 +311,41 @@ impl PrunePack {
         match todo {
             PackToDo::Undecided => panic!("not possible"),
             PackToDo::Keep => {
-                stats.blobs[tpe].used += pi.used_blobs as u64;
-                stats.blobs[tpe].unused += pi.unused_blobs as u64;
-                stats.size[tpe].used += pi.used_size as u64;
-                stats.size[tpe].unused += pi.unused_size as u64;
+                stats.blobs[tpe].used += u64::from(pi.used_blobs);
+                stats.blobs[tpe].unused += u64::from(pi.unused_blobs);
+                stats.size[tpe].used += u64::from(pi.used_size);
+                stats.size[tpe].unused += u64::from(pi.unused_size);
                 stats.packs.keep += 1;
             }
             PackToDo::Repack => {
-                stats.blobs[tpe].used += pi.used_blobs as u64;
-                stats.blobs[tpe].unused += pi.unused_blobs as u64;
-                stats.size[tpe].used += pi.used_size as u64;
-                stats.size[tpe].unused += pi.unused_size as u64;
+                stats.blobs[tpe].used += u64::from(pi.used_blobs);
+                stats.blobs[tpe].unused += u64::from(pi.unused_blobs);
+                stats.size[tpe].used += u64::from(pi.used_size);
+                stats.size[tpe].unused += u64::from(pi.unused_size);
                 stats.packs.repack += 1;
-                stats.blobs[tpe].repack += (pi.unused_blobs + pi.used_blobs) as u64;
-                stats.blobs[tpe].repackrm += pi.unused_blobs as u64;
-                stats.size[tpe].repack += (pi.unused_size + pi.used_size) as u64;
-                stats.size[tpe].repackrm += pi.unused_size as u64;
+                stats.blobs[tpe].repack += u64::from(pi.unused_blobs + pi.used_blobs);
+                stats.blobs[tpe].repackrm += u64::from(pi.unused_blobs);
+                stats.size[tpe].repack += u64::from(pi.unused_size + pi.used_size);
+                stats.size[tpe].repackrm += u64::from(pi.unused_size);
             }
 
             PackToDo::MarkDelete => {
-                stats.blobs[tpe].unused += pi.unused_blobs as u64;
-                stats.size[tpe].unused += pi.unused_size as u64;
-                stats.blobs[tpe].remove += pi.unused_blobs as u64;
-                stats.size[tpe].remove += pi.unused_size as u64;
+                stats.blobs[tpe].unused += u64::from(pi.unused_blobs);
+                stats.size[tpe].unused += u64::from(pi.unused_size);
+                stats.blobs[tpe].remove += u64::from(pi.unused_blobs);
+                stats.size[tpe].remove += u64::from(pi.unused_size);
             }
             PackToDo::Recover => {
                 stats.packs_to_delete.recover += 1;
-                stats.size_to_delete.recover += self.size as u64;
+                stats.size_to_delete.recover += u64::from(self.size);
             }
             PackToDo::Delete => {
                 stats.packs_to_delete.remove += 1;
-                stats.size_to_delete.remove += self.size as u64;
+                stats.size_to_delete.remove += u64::from(self.size);
             }
             PackToDo::KeepMarked => {
                 stats.packs_to_delete.keep += 1;
-                stats.size_to_delete.keep += self.size as u64;
+                stats.size_to_delete.keep += u64::from(self.size);
             }
         }
         self.to_do = todo;
@@ -599,7 +599,7 @@ impl Pruner {
             let blob_type = pi.blob_type;
 
             let total_repack_size: u64 = repack_size.into_values().sum();
-            if total_repack_size + pi.used_size as u64 >= max_repack
+            if total_repack_size + u64::from(pi.used_size) >= max_repack
                 || (self.stats.size.sum().unused_after_prune() < max_unused
                     && repack_reason == PartlyUsed
                     && blob_type == BlobType::Data)
@@ -608,10 +608,10 @@ impl Pruner {
                 pack.set_todo(PackToDo::Keep, &pi, &mut self.stats);
             } else if repack_reason == SizeMismatch {
                 resize_packs[blob_type].push((pi, index_num, pack_num));
-                repack_size[blob_type] += pi.used_size as u64;
+                repack_size[blob_type] += u64::from(pi.used_size);
             } else {
                 pack.set_todo(PackToDo::Repack, &pi, &mut self.stats);
-                repack_size[blob_type] += pi.used_size as u64;
+                repack_size[blob_type] += u64::from(pi.used_size);
                 do_repack[blob_type] = true;
             }
         }
@@ -619,7 +619,7 @@ impl Pruner {
             // packs in resize_packs are only repacked if we anyway repack this blob type or
             // if the target pack size is reached for the blob type.
             let todo = if do_repack[blob_type]
-                || repack_size[blob_type] > pack_sizer[blob_type].pack_size() as u64
+                || repack_size[blob_type] > u64::from(pack_sizer[blob_type].pack_size())
             {
                 PackToDo::Repack
             } else {
@@ -672,7 +672,7 @@ impl Pruner {
 
         // all remaining packs in existing_packs are unreferenced packs
         for size in self.existing_packs.values() {
-            self.stats.size_unref += *size as u64;
+            self.stats.size_unref += u64::from(*size);
         }
 
         Ok(())
@@ -827,7 +827,7 @@ impl Pruner {
         let size_after_prune = BlobTypeMap::init(|blob_type| {
             self.stats.size[blob_type].total_after_prune()
                 + self.stats.blobs[blob_type].total_after_prune()
-                    * HeaderEntry::ENTRY_LEN_COMPRESSED as u64
+                    * u64::from(HeaderEntry::ENTRY_LEN_COMPRESSED)
         });
 
         let tree_repacker = Repacker::new(
@@ -928,7 +928,7 @@ impl Pruner {
                         } else {
                             repacker.add(&pack.id, blob)?;
                         }
-                        p.inc(blob.length as u64);
+                        p.inc(u64::from(blob.length));
                     }
                     if opts.instant_delete {
                         delete_pack(pack);
@@ -1016,8 +1016,8 @@ impl Ord for PackInfo {
             // then order such that packs with highest
             // ratio unused/used space are picked first.
             // This is equivalent to ordering by unused / total space.
-            (other.unused_size as u64 * self.used_size as u64)
-                .cmp(&(self.unused_size as u64 * other.used_size as u64)),
+            (u64::from(other.unused_size) * u64::from(self.used_size))
+                .cmp(&(u64::from(self.unused_size) * u64::from(other.used_size))),
         )
     }
 }
diff --git a/src/commands/repair.rs b/src/commands/repair.rs
index 591adac..582e550 100644
--- a/src/commands/repair.rs
+++ b/src/commands/repair.rs
@@ -334,7 +334,7 @@ fn repair_tree<BE: DecryptWriteBackend>(
                             match be.get_data(&blob) {
                                 Some(ie) => {
                                     new_content.push(blob);
-                                    new_size += ie.data_length() as u64;
+                                    new_size += u64::from(ie.data_length());
                                 }
                                 None => {
                                     file_changed = true;
diff --git a/src/commands/repoinfo.rs b/src/commands/repoinfo.rs
index bbacbe4..9fffef0 100644
--- a/src/commands/repoinfo.rs
+++ b/src/commands/repoinfo.rs
@@ -33,13 +33,13 @@ pub(super) fn execute(repo: OpenRepository, _opts: Opts) -> Result<()> {
     impl Info {
         fn add(&mut self, ie: IndexEntry) {
             self.count += 1;
-            self.size += *ie.length() as u64;
-            self.data_size += ie.data_length() as u64;
+            self.size += u64::from(*ie.length());
+            self.data_size += u64::from(ie.data_length());
         }
 
         fn add_pack(&mut self, ip: &IndexPack) {
             self.pack_count += 1;
-            let size = ip.pack_size() as u64;
+            let size = u64::from(ip.pack_size());
             self.total_pack_size += size;
             self.min_pack_size = self.min_pack_size.min(size);
             self.max_pack_size = self.max_pack_size.max(size);
@@ -135,7 +135,7 @@ fn fileinfo(text: &str, be: &impl ReadBackend) -> Result<()> {
     for tpe in ALL_FILE_TYPES {
         let list = be.list_with_size(tpe)?;
         let count = list.len();
-        let size = list.iter().map(|f| f.1 as u64).sum();
+        let size = list.iter().map(|f| u64::from(f.1)).sum();
         table.add_row([format!("{:?}", tpe), count.to_string(), bytes(size)]);
         total_count += count;
         total_size += size;
diff --git a/src/index/binarysorted.rs b/src/index/binarysorted.rs
index 2b8243e..aa5cc45 100644
--- a/src/index/binarysorted.rs
+++ b/src/index/binarysorted.rs
@@ -110,7 +110,7 @@ impl Extend<IndexPack> for IndexCollector {
             let idx = self.0[blob_type].packs.len();
             self.0[blob_type].packs.push((p.id, size));
 
-            self.0[blob_type].total_size += size as u64;
+            self.0[blob_type].total_size += u64::from(size);
 
             match &mut self.0[blob_type].entries {
                 EntriesVariants::None => {}
diff --git a/src/repofile/keyfile.rs b/src/repofile/keyfile.rs
index cc3598d..9469e52 100644
--- a/src/repofile/keyfile.rs
+++ b/src/repofile/keyfile.rs
@@ -74,7 +74,7 @@ impl KeyFile {
             hostname,
             username,
             kdf: "scrypt".to_string(),
-            n: 2_u32.pow(params.log_n() as u32),
+            n: 2_u32.pow(u32::from(params.log_n())),
             r: params.r(),
             p: params.p(),
             created: with_created.then(Local::now),