diff --git a/src/pg_rad/objects.py b/src/pg_rad/objects.py
index 64b5665..3a6a1b1 100644
--- a/src/pg_rad/objects.py
+++ b/src/pg_rad/objects.py
@@ -62,4 +62,4 @@ class Source(Object):
         self.color = color
 
     def __repr__(self):
-        return f"Source(name={self.name}, A={self.activity} MBq, pos={(self.x, self.y, self.z)})"
\ No newline at end of file
+        return f"Source(name={self.name}, pos={(self.x, self.y, self.z)}, isotope={self.isotope.name}, A={self.activity} MBq)"
\ No newline at end of file