diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index 3bbc1e57d71d..ea891d12f8f4 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -643,7 +643,8 @@ static bool cs_etm_is_ete(struct perf_pmu *cs_etm_pmu, struct perf_cpu cpu)
 
 static __u64 cs_etm_get_legacy_trace_id(struct perf_cpu cpu)
 {
-	return CORESIGHT_LEGACY_CPU_TRACE_ID(cpu.cpu);
+	/* Wrap at 48 so that invalid trace IDs aren't saved into files. */
+	return CORESIGHT_LEGACY_CPU_TRACE_ID(cpu.cpu % 48);
 }
 
 static void cs_etm_save_etmv4_header(__u64 data[], struct auxtrace_record *itr, struct perf_cpu cpu)