diff --git a/ncdump/CMakeLists.txt b/ncdump/CMakeLists.txt
index 42358e9c67..255c41a998 100644
--- a/ncdump/CMakeLists.txt
+++ b/ncdump/CMakeLists.txt
@@ -251,6 +251,7 @@ endif()
 
     set_tests_properties(ncdump_tst_nccopy3 PROPERTIES DEPENDS
       "ncdump_tst_calendars;ncdump_run_utf8_tests;ncdump_tst_output;ncdump_tst_64bit;ncdump_run_tests;ncdump_tst_lengths")
+    set_tests_properties(ncdump_tst_nccopy3 PROPERTIES RUN_SERIAL TRUE)
 
   endif()
 
@@ -273,6 +274,7 @@ endif()
     add_sh_test(ncdump tst_nccopy4)
     set_tests_properties(ncdump_tst_nccopy4 PROPERTIES DEPENDS
       "ncdump_ncgen_tests;ncdump_tst_ncgen4;ncdump_tst_fillbug;ncdump_tst_netcdf4_4;ncdump_tst_h_scalar;ncdump_tst_netcdf4;ncdump_run_ncgen_tests;ncdump_tst_output;ncdump_tst_ncgen4;ncdump_sh_tst_fillbug;tst_comp;tst_comp2;tst_nans;tst_opaque_data;tst_create_files;tst_special_atts;ncdump_tst_nccopy3")
+    set_tests_properties(ncdump_tst_nccopy4 PROPERTIES RUN_SERIAL TRUE)
     add_sh_test(ncdump tst_calendars_nc4)
 
     set_tests_properties(ncdump_tst_nccopy4 PROPERTIES DEPENDS "")