diff --git a/e2e/volumes/test_sparsemap_cache_uniqueness.py b/e2e/volumes/test_sparsemap_cache_uniqueness.py
index 047f7795..c7b90696 100644
--- a/e2e/volumes/test_sparsemap_cache_uniqueness.py
+++ b/e2e/volumes/test_sparsemap_cache_uniqueness.py
@@ -2,6 +2,14 @@
 from siibra.volumes.sparsemap import SparseMap
 
 
+def test_cache_prefixes():
+    sparsemaps = [
+        mp for mp in siibra.maps
+        if isinstance(mp, siibra.volumes.sparsemap.SparseMap)
+    ]
+    assert len(sparsemaps) == len([mp._cache_prefix for mp in sparsemaps])
+
+
 def test_sparsemap_cache_uniqueness():
     mp157 = siibra.get_map("julich 3.0", "colin 27", "statistical", spec="157")
     mp175 = siibra.get_map("julich 3.0", "colin 27", "statistical", spec="175")