diff --git a/lib/efi_loader/efi_variable.c b/lib/efi_loader/efi_variable.c
index 7e0e7f0..64cf981 100644
--- a/lib/efi_loader/efi_variable.c
+++ b/lib/efi_loader/efi_variable.c
@@ -113,8 +113,8 @@
 	return hexstr;
 }
 
-static efi_status_t efi_to_native(char *native, s16 *variable_name,
-		efi_guid_t *vendor)
+static efi_status_t efi_to_native(char *native, u16 *variable_name,
+				  efi_guid_t *vendor)
 {
 	size_t len;
 
@@ -176,9 +176,9 @@
 }
 
 /* http://wiki.phoenix.com/wiki/index.php/EFI_RUNTIME_SERVICES#GetVariable.28.29 */
-efi_status_t EFIAPI efi_get_variable(s16 *variable_name,
-		efi_guid_t *vendor, u32 *attributes,
-		unsigned long *data_size, void *data)
+efi_status_t EFIAPI efi_get_variable(u16 *variable_name, efi_guid_t *vendor,
+				     u32 *attributes, efi_uintn_t *data_size,
+				     void *data)
 {
 	char native_name[MAX_NATIVE_VAR_NAME + 1];
 	efi_status_t ret;
@@ -250,9 +250,9 @@
 }
 
 /* http://wiki.phoenix.com/wiki/index.php/EFI_RUNTIME_SERVICES#GetNextVariableName.28.29 */
-efi_status_t EFIAPI efi_get_next_variable(
-		unsigned long *variable_name_size,
-		s16 *variable_name, efi_guid_t *vendor)
+efi_status_t EFIAPI efi_get_next_variable_name(efi_uintn_t *variable_name_size,
+					       u16 *variable_name,
+					       efi_guid_t *vendor)
 {
 	EFI_ENTRY("%p \"%ls\" %pUl", variable_name_size, variable_name, vendor);
 
@@ -260,16 +260,16 @@
 }
 
 /* http://wiki.phoenix.com/wiki/index.php/EFI_RUNTIME_SERVICES#SetVariable.28.29 */
-efi_status_t EFIAPI efi_set_variable(s16 *variable_name,
-		efi_guid_t *vendor, u32 attributes,
-		unsigned long data_size, void *data)
+efi_status_t EFIAPI efi_set_variable(u16 *variable_name, efi_guid_t *vendor,
+				     u32 attributes, efi_uintn_t data_size,
+				     void *data)
 {
 	char native_name[MAX_NATIVE_VAR_NAME + 1];
 	efi_status_t ret = EFI_SUCCESS;
 	char *val, *s;
 	u32 attr;
 
-	EFI_ENTRY("\"%ls\" %pUl %x %lu %p", variable_name, vendor, attributes,
+	EFI_ENTRY("\"%ls\" %pUl %x %zu %p", variable_name, vendor, attributes,
 		  data_size, data);
 
 	if (!variable_name || !vendor)