diff --git a/storage/filesystem/fat/source/FATFileSystem.cpp b/storage/filesystem/fat/source/FATFileSystem.cpp
index 9fefb0222f..3285d1a4ba 100644
--- a/storage/filesystem/fat/source/FATFileSystem.cpp
+++ b/storage/filesystem/fat/source/FATFileSystem.cpp
@@ -330,6 +330,11 @@ int FATFileSystem::unmount()
     }
 
     FRESULT res = f_mount(NULL, _fsid, 0);
+    int err = _ffs[_id]->deinit();
+    if (err) {
+        unlock();
+        return err;
+    }
     _ffs[_id] = NULL;
     _id = -1;
     unlock();