diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7eaf71c1..e6fb7747 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -153,5 +153,5 @@ gz_create_docs(
   API_MAINPAGE_MD "${CMAKE_BINARY_DIR}/api.md"
   TUTORIALS_MAINPAGE_MD "${CMAKE_BINARY_DIR}/tutorials.md"
   TAGFILES
-    "${IGNITION-MATH_DOXYGEN_TAGFILE} = ${IGNITION-MATH_API_URL}"
+    "${GZ-MATH_DOXYGEN_TAGFILE} = ${GZ-MATH_API_URL}"
   )