diff --git a/devices/clients/sst_client.py b/devices/clients/sst_client.py
index 17aad5dae1b3400f0e7f8d305d719c7a461ecb10..a63b0406733077a6c23e99b14407deba7a7693c0 100644
--- a/devices/clients/sst_client.py
+++ b/devices/clients/sst_client.py
@@ -202,7 +202,7 @@ class SST_collector(Thread):
         super().join(timeout)
 
     def process_packet(self, packet):
-        self.parameters["nof_packets"] += 1
+        self.parameters["nof_packets"] += numpy.uint64(1)
         self.parameters["last_packet_timestamp"] = numpy.uint64(int(time.time()))
         self.parameters["queue_fill_percentage"] = numpy.double(100 * self.queue.qsize() / self.queue.maxsize if self.queue.maxsize else 0)
 
@@ -210,28 +210,28 @@ class SST_collector(Thread):
             fields = StatisticsPacket(packet)
         except ValueError:
             # could not parse header
-            self.parameters["nof_invalid_packets"] += 1
+            self.parameters["nof_invalid_packets"] += numpy.uint64(1)
             return
 
         if fields.marker != 'S':
             # packet is not SST
-            self.parameters["nof_invalid_packets"] += 1
+            self.parameters["nof_invalid_packets"] += numpy.uint64(1)
             return
 
         input_index = fields.sst_signal_input_index
 
         if input_index >= self.MAX_INPUTS:
             # packet describes an input that is out of bounds for us
-            self.parameters["nof_invalid_packets"] += 1
+            self.parameters["nof_invalid_packets"] += numpy.uint64(1)
             return
 
         if fields.payload_error:
             # cannot trust the data if a payload error is reported
-            self.parameters["nof_payload_errors"][input_index] += 1
+            self.parameters["nof_payload_errors"][input_index] += numpy.uint64(1)
             return
 
         # process the packet
-        self.parameters["nof_valid_packets"][input_index]     += 1
+        self.parameters["nof_valid_packets"][input_index]     += numpy.uint64(1)
         self.parameters["last_values"][input_index][:fields.nof_statistics_per_packet] = fields.payload_sst
         self.parameters["last_timestamps"][input_index]       = numpy.float64(fields.timestamp().timestamp())
         self.parameters["integration_intervals"][input_index] = fields.integration_interval()