diff --git a/user_guide_src/requirements.txt b/user_guide_src/requirements.txt
index 4e76353..9dd84fb 100644
--- a/user_guide_src/requirements.txt
+++ b/user_guide_src/requirements.txt
@@ -1 +1 @@
-sphinxcontrib.phpdomain
\ No newline at end of file
+sphinxcontrib-phpdomain
\ No newline at end of file