diff --git a/gso/utils/types/geant_ids.py b/gso/utils/types/geant_ids.py
index adc3b19c0bb25afed690833f61f2f56decc4e1cc..194f57b0b2a1fade3c7eeec8d2831a4e700f44c1 100644
--- a/gso/utils/types/geant_ids.py
+++ b/gso/utils/types/geant_ids.py
@@ -34,7 +34,7 @@ def validate_id(value: str, prefix: str, field_name: str) -> str:
         err = f"{field_name} must have a numeric part after the prefix '{prefix}'."
         raise ValueError(err) from ValueError
 
-    if min_range <= numeric_part < max_range:
+    if min_range <= numeric_part <= max_range:
         err = f"{field_name} must not have a numeric part between 50000 and 99999."
         raise ValueError(err)