diff --git a/userspace/falco/stats_writer.cpp b/userspace/falco/stats_writer.cpp
index 0d8cde11..32c555a2 100644
--- a/userspace/falco/stats_writer.cpp
+++ b/userspace/falco/stats_writer.cpp
@@ -250,7 +250,7 @@ void stats_writer::collector::get_metrics_output_fields_additional(
 			for(uint32_t stat = 0; stat < nstats; stat++)
 			{
 				char metric_name[STATS_NAME_MAX] = "falco.";
-				strncat(metric_name, utilization[stat].name, sizeof(metric_name) - strlen(metric_name));
+				strncat(metric_name, utilization[stat].name, sizeof(metric_name) - strlen(metric_name) - 1);
 				switch(utilization[stat].type)
 				{
 				case STATS_VALUE_TYPE_U64:
@@ -313,7 +313,7 @@ void stats_writer::collector::get_metrics_output_fields_additional(
 			// todo: as we expand scap_stats_v2 prefix may be pushed to scap or we may need to expand
 			// functionality here for example if we add userspace syscall counters that should be prefixed w/ `falco.`
 			char metric_name[STATS_NAME_MAX] = "scap.";
-			strncat(metric_name, stats_v2[stat].name, sizeof(metric_name) - strlen(metric_name));
+			strncat(metric_name, stats_v2[stat].name, sizeof(metric_name) - strlen(metric_name) - 1);
 			switch(stats_v2[stat].type)
 			{
 			case STATS_VALUE_TYPE_U64: