diff --git a/fortran/testpar/thdf5.f90 b/fortran/testpar/thdf5.f90
index abb57977b1..7aa46f55d7 100644
--- a/fortran/testpar/thdf5.f90
+++ b/fortran/testpar/thdf5.f90
@@ -20,7 +20,7 @@
 
 !        Dataset dimensions
 
-           INTEGER, PARAMETER ::  DIM1 = 64, &
-                                  DIM2 = 128
+           INTEGER, PARAMETER ::  DIM1 = 120, &
+                                  DIM2 = 240
 
          END MODULE THDF5