diff --git a/fortran.nanorc b/fortran.nanorc
index 6854138..40623ee 100644
--- a/fortran.nanorc
+++ b/fortran.nanorc
@@ -1,6 +1,6 @@
 ## Here is an example for Fortran 90/95
 
-syntax "fortran" "\.(f|f90|f95|for)$" 
+syntax "fortran" "\.([Ff]|[Ff]90|[Ff]95|[Ff][Oo][Rr])$" 
 
 #color red "\<[A-Z_]a[0-9A-Z_]+\>" 
 color red "\<[0-9]+\>"