diff --git a/modules/mephit/git b/modules/mephit/git
index 6fc012e..85dac6a 100644
--- a/modules/mephit/git
+++ b/modules/mephit/git
@@ -10,7 +10,7 @@ proc ModulesHelp { } {
 module-whatis "use MEPHIT"
 
 prereq fgsl/1.6.0
-prereq mfem/4.7
+prereq --optional mfem/4.7
 
 setenv LIBNEO_DIR $env(CODE)/libneo/build
 setenv MEPHIT_DIR $env(CODE)/MEPHIT/build