diff --git a/sys/amd64/isa/clock.c b/sys/amd64/isa/clock.c
index 2d2391e4d0a..adc17435895 100644
--- a/sys/amd64/isa/clock.c
+++ b/sys/amd64/isa/clock.c
@@ -169,7 +169,7 @@ clkintr(struct trapframe *frame)
 #endif
 		hardclockintr(frame);
 	} else {
-		if (--pscnt == 0) {
+		if (--pscnt <= 0) {
 			pscnt = psratio;
 #ifdef SMP
 			if (smp_started)
@@ -262,7 +262,7 @@ rtcintr(struct trapframe *frame)
 
 	while (rtcin(RTC_INTR) & RTCIR_PERIOD) {
 		flag = 1;
-		if (--pscnt == 0) {
+		if (--pscnt <= 0) {
 			pscnt = psdiv;
 #ifdef SMP
 			if (smp_started)
diff --git a/sys/i386/isa/clock.c b/sys/i386/isa/clock.c
index 5e74796eb59..12e76e4b7ea 100644
--- a/sys/i386/isa/clock.c
+++ b/sys/i386/isa/clock.c
@@ -195,7 +195,7 @@ clkintr(struct trapframe *frame)
 #endif
 		hardclockintr(frame);
 	} else {
-		if (--pscnt == 0) {
+		if (--pscnt <= 0) {
 			pscnt = psratio;
 #ifdef SMP
 			if (smp_started)
@@ -293,7 +293,7 @@ rtcintr(struct trapframe *frame)
 
 	while (rtcin(RTC_INTR) & RTCIR_PERIOD) {
 		flag = 1;
-		if (--pscnt == 0) {
+		if (--pscnt <= 0) {
 			pscnt = psdiv;
 #ifdef SMP
 			if (smp_started)