diff --git a/bl2/ext/mcuboot/scripts/requirements.txt b/bl2/ext/mcuboot/scripts/requirements.txt
index 2e0f829..148fc3b 100644
--- a/bl2/ext/mcuboot/scripts/requirements.txt
+++ b/bl2/ext/mcuboot/scripts/requirements.txt
@@ -1,4 +1,4 @@
-cryptography
+cryptography>=3.1
 pyasn1
 pyyaml
 cbor>=1.0.0