diff --git a/tests/common/test_cmd_check_iocs.py b/tests/common/test_cmd_check_iocs.py
new file mode 100644
index 0000000..1bdd232
--- /dev/null
+++ b/tests/common/test_cmd_check_iocs.py
@@ -0,0 +1,139 @@
+# Mobile Verification Toolkit (MVT)
+# Copyright (c) 2021-2026 The MVT Authors.
+# Use of this software is governed by the MVT License 1.1 that can be found at
+#   https://license.mvt.re/1.1/
+
+import json
+import logging
+
+import pytest
+from click.testing import CliRunner
+
+from mvt.android.cli import cli as android_cli
+from mvt.android.command_modules import ANDROID_CHECK_IOCS_MODULES
+from mvt.common.cmd_check_iocs import CmdCheckIOCS
+from mvt.common.module import MVTModule
+from mvt.ios.cli import cli as ios_cli
+from mvt.ios.command_modules import IOS_CHECK_IOCS_MODULES
+
+# Keep the banner of the group callback from checking for updates online.
+OFFLINE = ["--disable-update-check", "--disable-indicator-update-check"]
+
+
+class CustomResultsModule(MVTModule):
+    """A custom module which declares the check-iocs pair of both platforms."""
+
+    slug = "custom_results"
+    supported_commands = (
+        ("ios", "check-backup"),
+        ("ios", "check-iocs"),
+        ("android", "check-iocs"),
+    )
+
+    checked: list = []
+
+    def run(self) -> None:
+        pass
+
+    def check_indicators(self) -> None:
+        self.checked.append(list(self.results))
+
+
+class BackupOnlyModule(MVTModule):
+    """A custom module which does not declare check-iocs."""
+
+    slug = "backup_only"
+    supported_commands = (("ios", "check-backup"),)
+
+    def check_indicators(self) -> None:
+        raise AssertionError("must not be re-checked")
+
+
+@pytest.mark.parametrize(
+    "platform, builtin_modules",
+    [("ios", IOS_CHECK_IOCS_MODULES), ("android", ANDROID_CHECK_IOCS_MODULES)],
+)
+def test_check_iocs_rechecks_the_stored_results_of_custom_modules(
+    platform, builtin_modules, tmp_path, caplog
+):
+    # check-iocs matches every <slug>.json in the results folder to the module
+    # with that slug, custom modules included, and runs its check_indicators()
+    # again over the stored results.
+    results = [{"domain": "example.org"}]
+    (tmp_path / "custom_results.json").write_text(json.dumps(results))
+    (tmp_path / "backup_only.json").write_text(json.dumps(results))
+    CustomResultsModule.checked.clear()
+
+    cmd = CmdCheckIOCS(
+        target_path=str(tmp_path),
+        custom_modules=[CustomResultsModule, BackupOnlyModule],
+        platform=platform,
+    )
+    cmd.modules = builtin_modules
+
+    with caplog.at_level(logging.INFO):
+        cmd.run()
+
+    assert CustomResultsModule.checked == [results]
+    assert (
+        'Loading results from "custom_results.json" with module CustomResultsModule'
+        in caplog.text
+    )
+    # A module declaring only check-backup is not part of check-iocs.
+    assert "backup_only.json" not in caplog.text
+
+
+def test_check_iocs_lists_custom_modules_declaring_the_command(caplog):
+    cmd = CmdCheckIOCS(
+        custom_modules=[CustomResultsModule, BackupOnlyModule],
+        platform="ios",
+    )
+    cmd.modules = IOS_CHECK_IOCS_MODULES
+
+    with caplog.at_level(logging.INFO):
+        cmd.list_modules()
+
+    assert "CustomResultsModule" in caplog.text
+    assert "BackupOnlyModule" not in caplog.text
+
+
+LOADED_MODULE = '''
+from mvt.common.module import MVTModule
+
+
+class LoadedResultsModule(MVTModule):
+    """A module loaded from a file with --load-module."""
+
+    slug = "loaded_results"
+    supported_commands = (("ios", "check-iocs"), ("android", "check-iocs"))
+
+    def run(self) -> None:
+        pass
+
+    def check_indicators(self) -> None:
+        self.log.warning("loaded module checked %d results", len(self.results))
+'''
+
+
+@pytest.mark.parametrize("cli", [ios_cli, android_cli], ids=["mvt-ios", "mvt-android"])
+def test_check_iocs_loads_custom_modules_from_a_file_on_each_cli(cli, tmp_path, caplog):
+    module_path = tmp_path / "loaded_module.py"
+    module_path.write_text(LOADED_MODULE)
+    results_folder = tmp_path / "results"
+    results_folder.mkdir()
+    (results_folder / "loaded_results.json").write_text(json.dumps([{"a": 1}]))
+
+    with caplog.at_level(logging.INFO):
+        result = CliRunner().invoke(
+            cli,
+            [
+                *OFFLINE,
+                "check-iocs",
+                "--load-module",
+                str(module_path),
+                str(results_folder),
+            ],
+        )
+
+    assert result.exit_code == 0, result.output
+    assert "loaded module checked 1 results" in caplog.text