diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 5c2ee36dd7111335191404666f6fd2c4f92b0426..7aee456668ed1cb0023bba8395281ff1b89cfb90 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,9 @@
 =========
 CHANGELOG
 =========
+-`Future`
+    Add Elastase, #45
+
 - `2.0.1 <https://gitlab.pasteur.fr/nmaillet/rpg/-/releases/2.0.1>`_
     Fix argparse bug preventing -h option to correctly be displayed
 
diff --git a/rpg/enzymes_definition.py b/rpg/enzymes_definition.py
index 2f5d9bbf938b58c77df37a536929e373b57632b0..b045e5b81bbd81ad44d8d64b49154be69beda733 100644
--- a/rpg/enzymes_definition.py
+++ b/rpg/enzymes_definition.py
@@ -1784,3 +1784,20 @@ ENZYME = enzyme.Enzyme(CPT_ENZ, "ProAlanase", ENZ, 0)
 # Add it to available enzymes
 AVAILABLE_ENZYMES.append(ENZYME)
 CPT_ENZ += 1
+
+
+
+# Elastase
+# https://france.promega.com/products/mass-spectrometry/proteases-and-surfactants/elastase/?catNum=V1891
+# RULES: after A, V, S, G, L, or I
+ENZ = []
+ENZ.append(rule.Rule(0, "A", True, 1))
+ENZ.append(rule.Rule(0, "V", True, 1))
+ENZ.append(rule.Rule(0, "S", True, 1))
+ENZ.append(rule.Rule(0, "G", True, 1))
+ENZ.append(rule.Rule(0, "L", True, 1))
+ENZ.append(rule.Rule(0, "I", True, 1))
+ENZYME = enzyme.Enzyme(CPT_ENZ, "Elastase", ENZ, 0)
+# Add it to available enzymes
+AVAILABLE_ENZYMES.append(ENZYME)
+CPT_ENZ += 1