diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
index b705637ca14b6da9a9cf69f0e9bb0eb79ff6e886..70a56580042bd6d0d778ea5dd000ae1385fb7053 100644
--- a/tools/testing/selftests/kvm/s390x/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
@@ -42,6 +42,13 @@ static void guest_code(void)
 		    " values did not match: 0x%llx, 0x%llx\n", \
 		    left->reg, right->reg)
 
+#define REG_COMPARE32(reg) \
+	TEST_ASSERT(left->reg == right->reg, \
+		    "Register " #reg \
+		    " values did not match: 0x%x, 0x%x\n", \
+		    left->reg, right->reg)
+
+
 static void compare_regs(struct kvm_regs *left, struct kvm_sync_regs *right)
 {
 	int i;
@@ -55,7 +62,7 @@ static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
 	int i;
 
 	for (i = 0; i < 16; i++)
-		REG_COMPARE(acrs[i]);
+		REG_COMPARE32(acrs[i]);
 
 	for (i = 0; i < 16; i++)
 		REG_COMPARE(crs[i]);
@@ -155,7 +162,7 @@ int main(int argc, char *argv[])
 		    "r11 sync regs value incorrect 0x%llx.",
 		    run->s.regs.gprs[11]);
 	TEST_ASSERT(run->s.regs.acrs[0]  == 1 << 11,
-		    "acr0 sync regs value incorrect 0x%llx.",
+		    "acr0 sync regs value incorrect 0x%x.",
 		    run->s.regs.acrs[0]);
 
 	vcpu_regs_get(vm, VCPU_ID, &regs);