diff --git a/ports/glm/portfile.cmake b/ports/glm/portfile.cmake
index 6b749b2de8..4780a1b393 100644
--- a/ports/glm/portfile.cmake
+++ b/ports/glm/portfile.cmake
@@ -1,3 +1,4 @@
+#header-only library
 include(vcpkg_common_functions)
 set(SOURCE_PATH ${CURRENT_BUILDTREES_DIR}/src/glm)
 vcpkg_download_distfile(ARCHIVE