diff --git a/odc/geo/crs.py b/odc/geo/crs.py
index 8d70a76c..b682fc78 100644
--- a/odc/geo/crs.py
+++ b/odc/geo/crs.py
@@ -242,7 +242,7 @@ def __str__(self) -> str:
         return self._str
 
     def __hash__(self) -> int:
-        return hash(self._str)
+        return hash(self._crs)
 
     def __repr__(self) -> str:
         return f"CRS('{self._str}')"