diff --git a/lib/libpmc/libpmc_pmu_util.c b/lib/libpmc/libpmc_pmu_util.c
index f451c37a059..11949a3ad3c 100644
--- a/lib/libpmc/libpmc_pmu_util.c
+++ b/lib/libpmc/libpmc_pmu_util.c
@@ -169,7 +169,7 @@ pmu_events_map_get(const char *cpuid)
 {
 	regex_t re;
 	regmatch_t pmatch[1];
-	size_t s, len;
+	size_t s;
 	char buf[64];
 	int match;
 	const struct pmu_events_map *pme;
@@ -193,8 +193,8 @@ pmu_events_map_get(const char *cpuid)
 		match = regexec(&re, buf, 1, pmatch, 0);
 		regfree(&re);
 		if (match == 0) {
-			len = pmatch[0].rm_eo - pmatch[0].rm_so;
-			if(len == strlen(buf))
+			if (pmatch[0].rm_so == 0 && (buf[pmatch[0].rm_eo] == 0
+			    || buf[pmatch[0].rm_eo] == '-'))
 				return (pme);
 		}
 	}
diff --git a/sys/dev/hwpmc/hwpmc_amd.c b/sys/dev/hwpmc/hwpmc_amd.c
index c1b850d459f..ca139b6fd8a 100644
--- a/sys/dev/hwpmc/hwpmc_amd.c
+++ b/sys/dev/hwpmc/hwpmc_amd.c
@@ -1073,7 +1073,7 @@ pmc_amd_initialize(void)
 	enum pmc_cputype cputype;
 	struct pmc_mdep *pmc_mdep;
 	enum pmc_class class;
-	int model;
+	int model, stepping;
 	char *name;
 
 	/*
@@ -1086,12 +1086,13 @@ pmc_amd_initialize(void)
 
 	name = NULL;
 	model = ((cpu_id & 0xF0000) >> 12) | ((cpu_id & 0xF0) >> 4);
+	stepping = cpu_id & 0xF;
 	if (CPUID_TO_FAMILY(cpu_id) == 0x17)
-		snprintf(pmc_cpuid, sizeof(pmc_cpuid), "AuthenticAMD-%d-%02X",
-				 CPUID_TO_FAMILY(cpu_id), model);
+		snprintf(pmc_cpuid, sizeof(pmc_cpuid), "AuthenticAMD-%d-%02X-%X",
+				 CPUID_TO_FAMILY(cpu_id), model, stepping);
 	if (CPUID_TO_FAMILY(cpu_id) == 0x18)
-		snprintf(pmc_cpuid, sizeof(pmc_cpuid), "HygonGenuine-%d-%02X",
-				 CPUID_TO_FAMILY(cpu_id), model);
+		snprintf(pmc_cpuid, sizeof(pmc_cpuid), "HygonGenuine-%d-%02X-%X",
+				 CPUID_TO_FAMILY(cpu_id), model, stepping);
 
 	switch (cpu_id & 0xF00) {
 #if	defined(__i386__)
diff --git a/sys/dev/hwpmc/hwpmc_intel.c b/sys/dev/hwpmc/hwpmc_intel.c
index 7a4839e3596..c16d6f94967 100644
--- a/sys/dev/hwpmc/hwpmc_intel.c
+++ b/sys/dev/hwpmc/hwpmc_intel.c
@@ -94,8 +94,8 @@ pmc_intel_initialize(void)
 	model = ((cpu_id & 0xF0000) >> 12) | ((cpu_id & 0xF0) >> 4);
 	stepping = cpu_id & 0xF;
 
-	snprintf(pmc_cpuid, sizeof(pmc_cpuid), "GenuineIntel-%d-%02X",
-			 (cpu_id & 0xF00) >> 8, model);
+	snprintf(pmc_cpuid, sizeof(pmc_cpuid), "GenuineIntel-%d-%02X-%X",
+			 (cpu_id & 0xF00) >> 8, model, stepping);
 	switch (cpu_id & 0xF00) {
 	case 0x600:		/* Pentium Pro, Celeron, Pentium II & III */
 		switch (model) {