diff --git a/MAC/TBB/lib/tbb_load_firmware.py b/MAC/TBB/lib/tbb_load_firmware.py
index 29cdfe224e6dac7c58b20215e248fd9d6ed2dc4f..d0778847648a123d43008c00873f2cce7ed62cdf 100755
--- a/MAC/TBB/lib/tbb_load_firmware.py
+++ b/MAC/TBB/lib/tbb_load_firmware.py
@@ -12,6 +12,7 @@ import subprocess
 import logging
 from lofar.mac.tbb.tbb_config import supported_modes, lcurun_command, tbb_command
 from lofar.common.lcu_utils import translate_user_station_string_into_station_list
+from lofar.common.subprocess_utils import check_output_returning_strings
 
 def load_tbb_firmware(stations, mode):
     logging.info('Loading TBB firmware for mode \"%s\"' % (mode))
@@ -49,7 +50,7 @@ def load_tbb_firmware(stations, mode):
         cmd = [tbb_command, '--imageinfo=%s' % str(board)]
         cmd = relay + cmd
         logging.info('Executing %s' % ' '.join(cmd))
-        logging.info(subprocess.check_output(cmd))
+        logging.info(subprocess.check_output_returning_strings(cmd))
 
 
 def parse_args():
diff --git a/MAC/TBB/lib/tbb_util.py b/MAC/TBB/lib/tbb_util.py
index cb8efe23f9e29ea40c54479e99e643e18c59ee6f..a4aef9348fdb58c277fac5d7baac53a056a7a11f 100644
--- a/MAC/TBB/lib/tbb_util.py
+++ b/MAC/TBB/lib/tbb_util.py
@@ -1,7 +1,8 @@
 from lofar.mac.tbb.tbb_config import *
 from lxml import etree
 from lofar.common.cep4_utils import *
-from subprocess import check_output
+from lofar.common.subprocess_utils import check_output_returning_strings
+
 import logging
 logger = logging.getLogger(__name__)
 
@@ -22,7 +23,7 @@ def get_cpu_nodes_running_tbb_datawriter_via_slurm():
     cmd = '''sacct --name=run-tbbwriter --user=lofarsys -o nodelist%128 -n -s R -X'''
     cmd = wrap_command_in_cep4_head_node_ssh_call(cmd)
     logger.debug('executing command: %s', ' '.join(cmd))
-    out = check_output(cmd).strip()
+    out = check_output_returning_strings(cmd).strip()
     logger.debug('  out: %s', out)
     return convert_slurm_nodes_string_to_node_number_list(out)