diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 496f42434327..9c086d743d34 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -4050,9 +4050,9 @@ bool evsel__set_needs_uniquify(struct evsel *counter, const struct perf_stat_con
 
 void evsel__uniquify_counter(struct evsel *counter)
 {
-	const char *name, *pmu_name;
-	char *new_name, *config;
-	int ret;
+	const char *name, *pmu_name, *config;
+	char *new_name;
+	int len, ret;
 
 	/* No uniquification necessary. */
 	if (!counter->needs_uniquify)
@@ -4066,15 +4066,23 @@ void evsel__uniquify_counter(struct evsel *counter)
 	counter->uniquified_name = true;
 
 	name = evsel__name(counter);
-	pmu_name = counter->pmu->name;
-	/* Already prefixed by the PMU name. */
-	if (!strncmp(name, pmu_name, strlen(pmu_name)))
-		return;
-
 	config = strchr(name, '/');
-	if (config) {
-		int len = config - name;
+	pmu_name = counter->pmu->name;
 
+	/* Already prefixed by the PMU name? */
+	len = pmu_name_len_no_suffix(pmu_name);
+
+	if (!strncmp(name, pmu_name, len)) {
+		/*
+		 * If the PMU name is there, then there is no sense in not
+		 * having a slash. Do this for robustness.
+		 */
+		if (config == NULL)
+			config = name - 1;
+
+		ret = asprintf(&new_name, "%s/%s", pmu_name, config + 1);
+	} else if (config) {
+		len = config - name;
 		if (config[1] == '/') {
 			/* case: event// */
 			ret = asprintf(&new_name, "%s/%.*s/%s", pmu_name, len, name, config + 2);
@@ -4086,7 +4094,7 @@ void evsel__uniquify_counter(struct evsel *counter)
 		config = strchr(name, ':');
 		if (config) {
 			/* case: event:.. */
-			int len = config - name;
+			len = config - name;
 
 			ret = asprintf(&new_name, "%s/%.*s/%s", pmu_name, len, name, config + 1);
 		} else {