diff --git a/docs/getting_started/prerequisites.rst b/docs/getting_started/prerequisites.rst
index 3e0c8ff..13e25cd 100644
--- a/docs/getting_started/prerequisites.rst
+++ b/docs/getting_started/prerequisites.rst
@@ -60,7 +60,7 @@
 
 The following libraries are required for Trusted Board Boot support:
 
-- mbed TLS == 2.16.2 (tag: ``mbedtls-2.16.2``)
+- mbed TLS == 2.18.0 (tag: ``mbedtls-2.18.0``)
 
 These tools are optional: