diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 7d86dcc941d98161d5b8fcbcf6e0a5943e0ddd56..8bc3e93292b1f3bebc20d5d9f9118f2135bc840a 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -739,7 +739,7 @@ static bool perf_pmu__valid_suffix(const char *pmu_name, char *tok)
 
 	/* Ensure we end in a number */
 	while (1) {
-		if (!isdigit(*p))
+		if (!isdigit(*p) && (*p != '_'))
 			return false;
 		if (*(++p) == 0)
 			break;