diff --git a/sys/boot/efi/boot1/zfs_module.c b/sys/boot/efi/boot1/zfs_module.c
index 363ae342a82..bf861ccaaf7 100644
--- a/sys/boot/efi/boot1/zfs_module.c
+++ b/sys/boot/efi/boot1/zfs_module.c
@@ -182,8 +182,8 @@ load(const char *filepath, dev_info_t *devinfo, void **bufp, size_t *bufsize)
 
 	if ((status = bs->AllocatePool(EfiLoaderData, (UINTN)st.st_size, &buf))
 	    != EFI_SUCCESS) {
-		printf("Failed to allocate load buffer %zd for pool '%s' for '%s' "
-		    "(%lu)\n", st.st_size, spa->spa_name, filepath, EFI_ERROR_CODE(status));
+		printf("Failed to allocate load buffer %jd for pool '%s' for '%s' "
+		    "(%lu)\n", (intmax_t)st.st_size, spa->spa_name, filepath, EFI_ERROR_CODE(status));
 		return (EFI_INVALID_PARAMETER);
 	}