diff --git a/indra/llmath/CMakeLists.txt b/indra/llmath/CMakeLists.txt
index 999bee0a3fe04a64d2b46562f24008acce55510a..6b82625d3954dffddbf34071eff235a842081529 100644
--- a/indra/llmath/CMakeLists.txt
+++ b/indra/llmath/CMakeLists.txt
@@ -63,6 +63,7 @@ set(llmath_HEADER_FILES
     llmath.h
     llmatrix3a.h
     llmatrix3a.inl
+    llmatrix4a.h
     llmodularmath.h
     lloctree.h
     llperlin.h