diff --git a/sys/dev/hwpmc/hwpmc_arm64.c b/sys/dev/hwpmc/hwpmc_arm64.c
index 4ae8645abaf6..15ea4f892ed0 100644
--- a/sys/dev/hwpmc/hwpmc_arm64.c
+++ b/sys/dev/hwpmc/hwpmc_arm64.c
@@ -195,6 +195,8 @@ arm64_read_pmc(int cpu, int ri, pmc_value_t *v)
 {
 	pmc_value_t tmp;
 	struct pmc *pm;
+	register_t s;
+	int reg;
 
 	KASSERT(cpu >= 0 && cpu < pmc_cpu_max(),
 	    ("[arm64,%d] illegal CPU value %d", __LINE__, cpu));
@@ -203,7 +205,23 @@ arm64_read_pmc(int cpu, int ri, pmc_value_t *v)
 
 	pm  = arm64_pcpu[cpu]->pc_arm64pmcs[ri].phw_pmc;
 
+	/*
+	 * Ensure we don't get interrupted while updating the overflow count.
+	 */
+	s = intr_disable();
 	tmp = arm64_pmcn_read(ri);
+	reg = (1 << ri);
+	if ((READ_SPECIALREG(pmovsclr_el0) & reg) != 0) {
+		/* Clear Overflow Flag */
+		WRITE_SPECIALREG(pmovsclr_el0, reg);
+		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
+			pm->pm_overflowcnt++;
+
+		/* Reread counter in case we raced. */
+		tmp = arm64_pmcn_read(ri);
+	}
+	tmp += 0x100000000llu * pm->pm_overflowcnt;
+	intr_restore(s);
 
 	PMCDBG2(MDP, REA, 2, "arm64-read id=%d -> %jd", ri, tmp);
 	if (PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
@@ -231,6 +249,7 @@ arm64_write_pmc(int cpu, int ri, pmc_value_t v)
 
 	PMCDBG3(MDP, WRI, 1, "arm64-write cpu=%d ri=%d v=%jx", cpu, ri, v);
 
+	pm->pm_overflowcnt = v >> 32;
 	arm64_pmcn_write(ri, v);
 
 	return 0;
@@ -342,9 +361,6 @@ arm64_intr(struct trapframe *tf)
 		pm = arm64_pcpu[cpu]->pc_arm64pmcs[ri].phw_pmc;
 		if (pm == NULL)
 			continue;
-		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm)))
-			continue;
-
 		/* Check if counter is overflowed */
 		reg = (1 << ri);
 		if ((READ_SPECIALREG(pmovsclr_el0) & reg) == 0)
@@ -355,6 +371,12 @@ arm64_intr(struct trapframe *tf)
 		isb();
 
 		retval = 1; /* Found an interrupting PMC. */
+
+		if (!PMC_IS_SAMPLING_MODE(PMC_TO_MODE(pm))) {
+			pm->pm_overflowcnt += 1;
+			continue;
+		}
+
 		if (pm->pm_state != PMC_STATE_RUNNING)
 			continue;