diff --git a/Carpet/CarpetIOHDF5/src/Output.cc b/Carpet/CarpetIOHDF5/src/Output.cc
index 9958213..e36fb32 100644
--- a/Carpet/CarpetIOHDF5/src/Output.cc
+++ b/Carpet/CarpetIOHDF5/src/Output.cc
@@ -147,12 +147,18 @@ int WriteVarUnchunked (const cGH* const cctkGH,
                                     request->compression_level :
                                     compression_level;
         if (compression_lvl) {
-          HDF5_ERROR (H5Pset_chunk (plist, group.dim, shape));
+          hsize_t chunk_shape[dim];
+          for (int d=0; d<dim; ++d) chunk_shape[d] = shape[d];
+          chunk_shape[0] = 1;
+          HDF5_ERROR (H5Pset_chunk (plist, group.dim, chunk_shape));
           HDF5_ERROR (H5Pset_deflate (plist, compression_lvl));
         }
         // enable checksums if requested
         if (use_checksums) {
-          HDF5_ERROR (H5Pset_chunk (plist, group.dim, shape));
+          hsize_t chunk_shape[dim];
+          for (int d=0; d<dim; ++d) chunk_shape[d] = shape[d];
+          chunk_shape[0] = 1;
+          HDF5_ERROR (H5Pset_chunk (plist, group.dim, chunk_shape));
           HDF5_ERROR (H5Pset_filter (plist, H5Z_FILTER_FLETCHER32, 0, 0, NULL));
         }
         HDF5_ERROR (dataset = H5Dcreate (outfile, datasetname.str().c_str(),
@@ -409,12 +415,18 @@ int WriteVarChunkedSequential (const cGH* const cctkGH,
                                       request->compression_level :
                                       compression_level;
           if (compression_lvl) {
-            HDF5_ERROR (H5Pset_chunk (plist, group.dim, shape));
+            hsize_t chunk_shape[dim];
+            for (int d=0; d<dim; ++d) chunk_shape[d] = shape[d];
+            chunk_shape[0] = 1;
+            HDF5_ERROR (H5Pset_chunk (plist, group.dim, chunk_shape));
             HDF5_ERROR (H5Pset_deflate (plist, compression_lvl));
           }
           // enable checksums if requested
           if (use_checksums) {
-            HDF5_ERROR (H5Pset_chunk (plist, group.dim, shape));
+            hsize_t chunk_shape[dim];
+            for (int d=0; d<dim; ++d) chunk_shape[d] = shape[d];
+            chunk_shape[0] = 1;
+            HDF5_ERROR (H5Pset_chunk (plist, group.dim, chunk_shape));
             HDF5_ERROR (H5Pset_filter (plist, H5Z_FILTER_FLETCHER32, 0, 0, NULL));
           }
           HDF5_ERROR (dataspace = H5Screate_simple (group.dim, shape, NULL));
@@ -572,12 +584,18 @@ int WriteVarChunkedParallel (const cGH* const cctkGH,
                                   request->compression_level :
                                   compression_level;
       if (compression_lvl) {
-        HDF5_ERROR (H5Pset_chunk (plist, group.dim, shape));
+        hsize_t chunk_shape[dim];
+        for (int d=0; d<dim; ++d) chunk_shape[d] = shape[d];
+        chunk_shape[0] = 1;
+        HDF5_ERROR (H5Pset_chunk (plist, group.dim, chunk_shape));
         HDF5_ERROR (H5Pset_deflate (plist, compression_lvl));
       }
       // enable checksums if requested
       if (use_checksums) {
-        HDF5_ERROR (H5Pset_chunk (plist, group.dim, shape));
+        hsize_t chunk_shape[dim];
+        for (int d=0; d<dim; ++d) chunk_shape[d] = shape[d];
+        chunk_shape[0] = 1;
+        HDF5_ERROR (H5Pset_chunk (plist, group.dim, chunk_shape));
         HDF5_ERROR (H5Pset_filter (plist, H5Z_FILTER_FLETCHER32, 0, 0, NULL));
       }
       HDF5_ERROR (dataspace = H5Screate_simple (group.dim, shape, NULL));