diff --git a/spack.yaml b/spack.yaml
index 48650471bd914385839b1e04dd921b5c48f9845f..adfe9d37adfe9d68ff4c8f60f8ef14f3fcd47665 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -50,8 +50,8 @@ spack:
       paths:
         cc: /usr/bin/gcc
         cxx: /usr/bin/g++
-        f77: /usr/bin/gfortran
-        fc: /usr/bin/gfortran
+        f77: 
+        fc: 
       flags: {}
       operating_system: ubuntu18.04
       target: x86_64