diff --git a/stratosphere/ams_mitm/source/fs_mitm/fsmitm_service.cpp b/stratosphere/ams_mitm/source/fs_mitm/fsmitm_service.cpp
index 5804a6b..40b4b70 100644
--- a/stratosphere/ams_mitm/source/fs_mitm/fsmitm_service.cpp
+++ b/stratosphere/ams_mitm/source/fs_mitm/fsmitm_service.cpp
@@ -99,7 +99,7 @@
         FsStorage bis_storage;
         rc = fsOpenBisStorageFwd(this->forward_service.get(), &bis_storage, bis_partition_id);
         if (R_SUCCEEDED(rc)) {
-            const bool is_sysmodule = this->title_id < 0x0100000000001000;
+            const bool is_sysmodule = this->title_id < 0x0100000000001000ul;
             const bool has_bis_write_flag = Utils::HasFlag(this->title_id, "bis_write");
             const bool has_cal0_read_flag = Utils::HasFlag(this->title_id, "cal_read");
             if (bis_partition_id == BisStorageId_Boot0) {
diff --git a/stratosphere/ams_mitm/source/utils.cpp b/stratosphere/ams_mitm/source/utils.cpp
index 976a82e..1f19ede 100644
--- a/stratosphere/ams_mitm/source/utils.cpp
+++ b/stratosphere/ams_mitm/source/utils.cpp
@@ -392,14 +392,14 @@
         
         memset(flag_path, 0, sizeof(flag_path));
         snprintf(flag_path, sizeof(flag_path) - 1, "flags/%s.flag", flag);
-        if (OpenSdFileForAtmosphere(tid, flag_path, FS_OPEN_READ, &f)) {
+        if (R_SUCCEEDED(OpenSdFileForAtmosphere(tid, flag_path, FS_OPEN_READ, &f))) {
             fsFileClose(&f);
             return true;
         }
         
         /* TODO: Deprecate. */
         snprintf(flag_path, sizeof(flag_path) - 1, "%s.flag", flag);
-        if (OpenSdFileForAtmosphere(tid, flag_path, FS_OPEN_READ, &f)) {
+        if (R_SUCCEEDED(OpenSdFileForAtmosphere(tid, flag_path, FS_OPEN_READ, &f))) {
             fsFileClose(&f);
             return true;
         }
@@ -412,7 +412,7 @@
         FsFile f;
         char flag_path[FS_MAX_PATH] = {0};
         snprintf(flag_path, sizeof(flag_path), "/atmosphere/flags/%s.flag", flag);
-        if (fsFsOpenFile(&g_sd_filesystem, flag_path, FS_OPEN_READ, &f)) {
+        if (R_SUCCEEDED(fsFsOpenFile(&g_sd_filesystem, flag_path, FS_OPEN_READ, &f))) {
             fsFileClose(&f);
             return true;
         }