diff --git a/sys/arm/arm/generic_timer.c b/sys/arm/arm/generic_timer.c
index b13080d57bb..2739c5b6da8 100644
--- a/sys/arm/arm/generic_timer.c
+++ b/sys/arm/arm/generic_timer.c
@@ -92,6 +92,7 @@ __FBSDID("$FreeBSD$");
 struct arm_tmr_softc {
 	struct resource		*res[4];
 	void			*ihl[4];
+	uint64_t		(*get_cntxct)(bool);
 	uint32_t		clkfreq;
 	struct eventtimer	et;
 	bool			physical;
@@ -141,6 +142,28 @@ get_freq(void)
 	return (get_el0(cntfrq));
 }
 
+static uint64_t
+get_cntxct_a64_unstable(bool physical)
+{
+	uint64_t val
+;
+	isb();
+	if (physical) {
+		do {
+			val = get_el0(cntpct);
+		}
+		while (((val + 1) & 0x7FF) <= 1);
+	}
+	else {
+		do {
+			val = get_el0(cntvct);
+		}
+		while (((val + 1) & 0x7FF) <= 1);
+	}
+
+	return (val);
+}
+
 static uint64_t
 get_cntxct(bool physical)
 {
@@ -226,7 +249,7 @@ static unsigned
 arm_tmr_get_timecount(struct timecounter *tc)
 {
 
-	return (get_cntxct(arm_tmr_sc->physical));
+	return (arm_tmr_sc->get_cntxct(arm_tmr_sc->physical));
 }
 
 static int
@@ -379,6 +402,7 @@ arm_tmr_attach(device_t dev)
 	if (arm_tmr_sc)
 		return (ENXIO);
 
+	sc->get_cntxct = &get_cntxct_a64_unstable;
 #ifdef FDT
 	/* Get the base clock frequency */
 	node = ofw_bus_get_node(dev);
@@ -387,6 +411,13 @@ arm_tmr_attach(device_t dev)
 		    sizeof(clock));
 		if (error > 0)
 			sc->clkfreq = clock;
+
+		if (OF_hasprop(node, "allwinner,sun50i-a64-unstable-timer")) {
+			sc->get_cntxct = &get_cntxct_a64_unstable;
+			if (bootverbose)
+				device_printf(dev,
+				    "Enabling allwinner unstable timer workaround\n");
+		}
 	}
 #endif
 
@@ -518,10 +549,10 @@ arm_tmr_do_delay(int usec, void *arg)
 	else
 		counts = usec * counts_per_usec;
 
-	first = get_cntxct(sc->physical);
+	first = sc->get_cntxct(sc->physical);
 
 	while (counts > 0) {
-		last = get_cntxct(sc->physical);
+		last = sc->get_cntxct(sc->physical);
 		counts -= (int32_t)(last - first);
 		first = last;
 	}