diff --git a/include/test.mk b/include/test.mk
index c0e240951..c37b84466 100644
--- a/include/test.mk
+++ b/include/test.mk
@@ -92,7 +92,7 @@ test-mock-variables: CFLAGS+=-DHAVE_SHIM_LOCK_GUID
 test-mok-mirror_FILES = mok.c globals.c tpm.c lib/guid.c lib/variables.c mock-variables.c
 test-mok-mirror: CFLAGS+=-DHAVE_START_IMAGE -DHAVE_SHIM_LOCK_GUID
 
-test-sbat_FILES = csv.c lib/variables.c lib/guid.c sbat_var.S
+test-sbat_FILES = csv.c lib/variables.c lib/guid.c sbat_var.S mock-variables.c
 test-sbat :: CFLAGS+=-DHAVE_GET_VARIABLE -DHAVE_GET_VARIABLE_ATTR -DHAVE_SHIM_LOCK_GUID
 
 test-str_FILES = lib/string.c
diff --git a/sbat_var.S b/sbat_var.S
index a115077ae..2a813a403 100644
--- a/sbat_var.S
+++ b/sbat_var.S
@@ -14,7 +14,9 @@ sbat_var_payload_header:
 .Lsbat_var_payload_header_end:
 	.balign	1, 0
 .Lsbat_var_previous:
-	.asciz SBAT_VAR_PREVIOUS
+	.ascii SBAT_VAR_PREVIOUS
+	.byte	0
 	.balign	1, 0
 .Lsbat_var_latest:
-	.asciz SBAT_VAR_LATEST
+	.ascii SBAT_VAR_LATEST
+	.byte 0
diff --git a/test-sbat.c b/test-sbat.c
index 72bebe7ae..65bc6a84b 100644
--- a/test-sbat.c
+++ b/test-sbat.c
@@ -1107,6 +1107,36 @@ test_preserve_sbat_uefi_variable_bad_short(void)
 		return 0;
 }
 
+static int
+test_sbat_var_asciz(void)
+{
+	EFI_STATUS status;
+	char buf[1024] = "";
+	UINT32 attrs = 0;
+	UINTN size = sizeof(buf);
+	char expected[] = SBAT_VAR_PREVIOUS;
+
+	status = set_sbat_uefi_variable();
+	if (status != EFI_SUCCESS)
+		return -1;
+
+	status = RT->GetVariable(SBAT_VAR_NAME, &SHIM_LOCK_GUID, &attrs, &size, buf);
+	if (status != EFI_SUCCESS)
+		return -1;
+
+	/*
+	 * this should be enough to get past "sbat,", which handles the
+	 * first error.
+	 */
+	if (size < (strlen(SBAT_VAR_SIG) + 2) || size != strlen(expected))
+		return -1;
+
+	if (strncmp(expected, buf, size) != 0)
+		return -1;
+
+	return 0;
+}
+
 int
 main(void)
 {
@@ -1155,6 +1185,8 @@ main(void)
 	test(test_preserve_sbat_uefi_variable_version_older);
 	test(test_preserve_sbat_uefi_variable_version_olderlonger);
 
+	test(test_sbat_var_asciz);
+
 	return 0;
 }