diff --git a/src/instruction.c b/src/instruction.c
index 4ee12da..350a730 100644
--- a/src/instruction.c
+++ b/src/instruction.c
@@ -353,8 +353,7 @@ instruction_data_read_1(rk65c02emu_t *e, instrdef_t *id, instruction_t *i)
 		rv = bus_read_1(e->bus, i->op1);
 		break;
 	case ZPX:
-		/* XXX: wraps around zero page? */
-		rv = bus_read_1(e->bus, i->op1 + e->regs.X);
+		rv = bus_read_1(e->bus, (uint8_t) (i->op1 + e->regs.X));
 		break;
 	case ZPY:
 		rv = bus_read_1(e->bus, i->op1 + e->regs.Y);
diff --git a/test/test_emulation.c b/test/test_emulation.c
index bc9d381..34d1fa5 100644
--- a/test/test_emulation.c
+++ b/test/test_emulation.c
@@ -1409,6 +1409,7 @@ ATF_TC_BODY(emul_wrap_zpx, tc)
 {
 	rk65c02emu_t e;
 	bus_t b;
+	uint16_t i;
 
 	b = bus_init_with_default_devs();
 	e = rk65c02_init(&b);
@@ -1422,6 +1423,13 @@ ATF_TC_BODY(emul_wrap_zpx, tc)
 	ATF_CHECK(bus_read_1(&b, 0x00) == 0xAA);
 	ATF_CHECK(bus_read_1(&b, 0x01) == 0xAA);
 	ATF_CHECK(bus_read_1(&b, 0x7E) == 0xAA);
+
+	i = 0x200;
+
+	while (i < 0x205) {
+		ATF_CHECK(bus_read_1(&b, i) == 0xAA);
+		i++;
+	}
 }
 
 ATF_TP_ADD_TCS(tp)
diff --git a/test/test_emulation_wrap_zpx.s b/test/test_emulation_wrap_zpx.s
index 17f5db2..8c0bf9d 100644
--- a/test/test_emulation_wrap_zpx.s
+++ b/test/test_emulation_wrap_zpx.s
@@ -3,5 +3,16 @@ start:	sta 0x10,X
 	sta 0x81,X
 	sta 0x82,X
 	sta 0xFF,X
+
+	ldy 0x10,X
+	sty 0x200
+	ldy 0x80,X
+	sty 0x201
+	ldy 0x81,X
+	sty 0x202
+	ldy 0x82,X
+	sty 0x203
+	ldy 0xFF,X
+	sty 0x204
 	stp