diff --git a/src/lib/charm/gluster/block.py b/src/lib/charm/gluster/block.py
index 71a2961..ccb0c84 100644
--- a/src/lib/charm/gluster/block.py
+++ b/src/lib/charm/gluster/block.py
@@ -181,8 +181,8 @@ class Btrfs(Filesystem):
         handle to access it.
         """
         device = brick_device.dev_path
-        arg_list = ["mkfs.btrfs", "-m", self.metadata_profile,
-                    "-l", self.leaf_size, "-n", self.node_size,
+        arg_list = ["mkfs.btrfs", "-m", str(self.metadata_profile),
+                    "-l", self.leaf_size, "-n", str(self.node_size),
                     device]
         # Check if mkfs.btrfs is installed
         if not os.path.exists("/sbin/mkfs.btrfs"):
@@ -225,10 +225,10 @@ class Ext4(Filesystem):
         handle to access it.
         """
         device = brick_device.dev_path
-        arg_list = ["mkfs.ext4", "-m", self.reserved_blocks_percentage]
+        arg_list = ["mkfs.ext4", "-m", str(self.reserved_blocks_percentage)]
         if self.inode_size is not None:
             arg_list.append("-I")
-            arg_list.append(self.inode_size)
+            arg_list.append(str(self.inode_size))
 
         if self.stride is not None:
             arg_list.append("-E")
diff --git a/src/lib/charm/gluster/lib.py b/src/lib/charm/gluster/lib.py
index b6d4b03..26145a5 100644
--- a/src/lib/charm/gluster/lib.py
+++ b/src/lib/charm/gluster/lib.py
@@ -227,7 +227,7 @@ def finish_initialization(device_path: str) -> Result:
     log("device_info: {}".format(device_info.value), INFO)
 
     # Zfs automatically handles mounting the device
-    if filesystem_type is not Zfs:
+    if filesystem_type is not filesystem_type.Zfs:
         log("Mounting block device {} at {}".format(device_path, mount_path),
             INFO)
         status_set(workload_state="maintenance",
@@ -354,7 +354,7 @@ def initialize_storage(device: BrickDevice) -> Result:
     inode_size = config("inode_size")
 
     # Format with the default XFS unless told otherwise
-    if filesystem_type is Xfs:
+    if filesystem_type is FilesystemType.Xfs:
         log("Formatting block device with XFS: {}".format(device.dev_path),
             INFO)
         status_set(workload_state="maintenance",
@@ -368,7 +368,7 @@ def initialize_storage(device: BrickDevice) -> Result:
             stripe_width=stripe_width,
         )
         return Ok(xfs.format(brick_device=device))
-    elif filesystem_type is Ext4:
+    elif filesystem_type is FilesystemType.Ext4:
         log("Formatting block device with Ext4: {}".format(device.dev_path),
             INFO)
         status_set(workload_state="maintenance",
@@ -383,7 +383,7 @@ def initialize_storage(device: BrickDevice) -> Result:
         )
         return Ok(ext4.format(brick_device=device))
 
-    elif filesystem_type is Btrfs:
+    elif filesystem_type is FilesystemType.Btrfs:
         log("Formatting block device with Btrfs: {}".format(device.dev_path),
             INFO)
         status_set(workload_state="maintenance",
@@ -395,7 +395,7 @@ def initialize_storage(device: BrickDevice) -> Result:
             node_size=0,
             metadata_profile=MetadataProfile.Single)
         return Ok(btrfs.format(brick_device=device))
-    elif filesystem_type is Zfs:
+    elif filesystem_type is FilesystemType.Zfs:
         log("Formatting block device with ZFS: {:}".format(device.dev_path),
             INFO)
         status_set(workload_state="maintenance",
@@ -407,7 +407,9 @@ def initialize_storage(device: BrickDevice) -> Result:
         )
         return Ok(zfs.format(brick_device=device))
     else:
-        log("Formatting block device with XFS: {}".format(device.dev_path),
+        log(
+            "Unknown filesystem. Defaulting to formatting with XFS: {}".format(
+                device.dev_path),
             INFO)
         status_set(workload_state="maintenance",
                    message="Formatting block device with XFS: {}".format(