diff --git a/CREDITS b/CREDITS
index 875b725..273b895 100644
--- a/CREDITS
+++ b/CREDITS
@@ -39,3 +39,13 @@ epubgrep makes direct use of the following libraries and programs:
     From: Ihor Kalnytskyi
           https://termcolor.readthedocs.io/
     License: BSD-3-Clause
+
+  pugixml
+    From: pugixml community
+          https://pugixml.org/
+    License: MIT
+
+  nlohmann-json
+    From: Niels Lohmann and community
+          https://github.com/nlohmann/json
+    License: MIT