diff --git a/src/install/drives.rs b/src/install/drives.rs
index 85ce385..1151537 100644
--- a/src/install/drives.rs
+++ b/src/install/drives.rs
@@ -137,7 +137,9 @@ pub fn has_filesystem(dev: &str) -> Option<String> {
 
     if let Some(dev_entry) = dev_entry {
         if let Some(fs) = dev_entry.as_object().unwrap().get("fstype") {
-            return Some(fs.to_string());
+            if matches!(fs, serde_json::Value::String(_)) {
+                return Some(fs.to_string());
+            }
         }
     }