diff --git a/docs/getting_started/tools-build.rst b/docs/getting_started/tools-build.rst
index c050f58..daf7e06 100644
--- a/docs/getting_started/tools-build.rst
+++ b/docs/getting_started/tools-build.rst
@@ -1,6 +1,16 @@
 Building Supporting Tools
 =========================
 
+.. note::
+
+    OpenSSL 3.0 is needed in order to build the tools. A custom installation
+    can be used if not updating the OpenSSL version on the OS. In order to do
+    this, use the ``OPENSSL_DIR`` variable after the ``make`` command to
+    indicate the location of the custom OpenSSL build. Then, to run the tools,
+    use the ``LD_LIBRARY_PATH`` to indicate the location of the built
+    libraries. More info about ``OPENSSL_DIR`` can be found at
+    :ref:`Build Options`.
+
 Building and using the FIP tool
 -------------------------------
 
@@ -164,4 +174,4 @@
 
 --------------
 
-*Copyright (c) 2019, Arm Limited. All rights reserved.*
+*Copyright (c) 2019-2022, Arm Limited. All rights reserved.*