diff --git a/build/make.default b/build/make.default
index 144ac77..46af636 100644
--- a/build/make.default
+++ b/build/make.default
@@ -20,11 +20,10 @@ SIGNALS      = N
 #
 MPI          = N
 
-# output data format
+#   OUTPUT       - the format of the alternative data output;
+#                  supported alternative formats: HDF5
 #
-#   OUTPUT       - the format of output data; so far only HDF5
-#
-OUTPUT       = HDF5
+OUTPUT       =
 
 #-------------------------------------------------------------------------------
 #
@@ -39,4 +38,4 @@ NDIMS        = 2
 #
 # path for temporary files during compilation (uncomment if you wish to use it)
 #
-#OBJSDIR := /tmp/${USER}/amun-code/objects
\ No newline at end of file
+#OBJSDIR := /tmp/${USER}/amun-code/objects