diff --git a/usr.sbin/pciconf/pciconf.c b/usr.sbin/pciconf/pciconf.c
--- a/usr.sbin/pciconf/pciconf.c
+++ b/usr.sbin/pciconf/pciconf.c
@@ -1153,7 +1153,7 @@
 	case 1:
 		db = (uint8_t *)(uintptr_t)((uintptr_t)pbm.pbm_map_base +
 		    pbm.pbm_bar_off + start * width);
-		for (a = 0; a < count; a += width, db++) {
+		for (a = 0; a < count; a++, db++) {
 			res = fwrite(db, width, 1, stdout);
 			if (res != 1) {
 				errx(1, "error writing to stdout");
@@ -1164,7 +1164,7 @@
 	case 2:
 		dh = (uint16_t *)(uintptr_t)((uintptr_t)pbm.pbm_map_base +
 		    pbm.pbm_bar_off + start * width);
-		for (a = 0; a < count; a += width, dh++) {
+		for (a = 0; a < count; a++, dh++) {
 			res = fwrite(dh, width, 1, stdout);
 			if (res != 1) {
 				errx(1, "error writing to stdout");
@@ -1175,7 +1175,7 @@
 	case 4:
 		dd = (uint32_t *)(uintptr_t)((uintptr_t)pbm.pbm_map_base +
 		    pbm.pbm_bar_off + start * width);
-		for (a = 0; a < count; a += width, dd++) {
+		for (a = 0; a < count; a ++, dd++) {
 			res = fwrite(dd, width, 1, stdout);
 			if (res != 1) {
 				errx(1, "error writing to stdout");
@@ -1186,7 +1186,7 @@
 	case 8:
 		dx = (uint64_t *)(uintptr_t)((uintptr_t)pbm.pbm_map_base +
 		    pbm.pbm_bar_off + start * width);
-		for (a = 0; a < count; a += width, dx++) {
+		for (a = 0; a < count; a++, dx++) {
 			res = fwrite(dx, width, 1, stdout);
 			if (res != 1) {
 				errx(1, "error writing to stdout");