diff --git a/kernelci/api/helper.py b/kernelci/api/helper.py
index 5c78807fef..43648f4621 100644
--- a/kernelci/api/helper.py
+++ b/kernelci/api/helper.py
@@ -391,11 +391,18 @@ def should_create_node(self, rules, node, parent=None):
     def _fsanitize_node_fields(self, node, field_name):
         """
         Sanitize node fields to escape curly braces
+        We need to walk over multiple levels of the node dict to find the field
+        and escape the curly braces.
         """
-        if field_name in node:
-            # double each found bracket to escape it
-            node[field_name] = node[field_name].replace('}', '}}')
-            node[field_name] = node[field_name].replace('{', '{{')
+        if isinstance(node, dict):
+            for k, val in node.items():
+                if k == field_name and isinstance(val, str):
+                    node[k] = val.replace('}', '}}').replace('{', '{{')
+                else:
+                    self._fsanitize_node_fields(val, field_name)
+        elif isinstance(node, list):
+            for item in node:
+                self._fsanitize_node_fields(item, field_name)
         return node
 
     def create_job_node(self, job_config, input_node,
diff --git a/tests/api/test_apihelper.py b/tests/api/test_apihelper.py
new file mode 100644
index 0000000000..411996ffea
--- /dev/null
+++ b/tests/api/test_apihelper.py
@@ -0,0 +1,97 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# Copyright (C) 2025 Collabora Limited
+# Author: Denys Fedoryshchenko <denys.f@collabora.com>
+
+# pylint: disable=C0301
+
+""" Test the APIHelper class """
+
+from kernelci.api.helper import APIHelper
+import kernelci.api
+
+
+def test_apihelper():
+    """
+    Test the APIHelper class
+    (i know i should not be testing private methods, but this is it for now)
+    """
+    node = {
+        "id": "6823c3bafef071f536b6ec3c",
+        "kind": "checkout",
+        "name": "checkout",
+        "path": ["checkout"],
+        "group": None,
+        "parent": None,
+        "state": "done",
+        "result": "pass",
+        "artifacts": {
+            "tarball": "https://files.kernelci.org/linux-mainline-master-v6.15-rc6-52-g9f35e33144ae5.tar.gz"  # noqa: E501
+        },
+        "data": {
+            "kernel_revision": {
+                "tree": "mainline",
+                "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git",
+                "branch": "master",
+                "commit": "9f35e33144ae5377d6a8de86dd3bd4d995c6ac65",
+                "describe": "v6.15-rc6-52-g9f35e33144ae5",
+                "version": {
+                    "version": 6,
+                    "patchlevel": 15,
+                    "extra": "-rc6-52-g9f35e33144ae5",
+                },
+                "commit_tags": [],
+                "commit_message": (
+                    "x86/its: Fix build errors when CONFIG_MODULES=n\n\n"
+                    "Fix several build errors when CONFIG_MODULES=n, including the following:\n\n"
+                    "../arch/x86/kernel/alternative.c:195:25: error: incomplete definition of type 'struct module'\n"  # noqa: E501
+                    "  195 |         for (int i = 0; i < mod->its_num_pages; i++) {\n\n"
+                    'Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches")\n'
+                    "Cc: stable@vger.kernel.org\n"
+                    "Signed-off-by: Eric Biggers \n"
+                    "Acked-by: Dave Hansen \n"
+                    "Tested-by: Steven Rostedt (Google) \n"
+                    "Reviewed-by: Alexandre Chartre \n"
+                    "Signed-off-by: Linus Torvalds "
+                ),
+                "tip_of_branch": True,
+            },
+            "architecture_filter": ["x86_64", "arm64", "arm"],
+        },
+        "debug": {},
+        "jobfilter": None,
+        "platform_filter": [],
+        "created": "2025-05-13T22:12:10.336000",
+        "updated": "2025-05-13T22:26:20.157000",
+        "timeout": "2025-05-13T23:12:10.327000",
+        "holdoff": "2025-05-13T22:25:56.224000",
+        "owner": "production",
+        "submitter": "service:pipeline",
+        "treeid": "c1c7b00a59158432a35f2458f745bfbf142bf513801766850c30f65fdb86d5ab",
+        "user_groups": [],
+        "processed_by_kcidb_bridge": True,
+    }
+
+    configs = kernelci.config.load("tests/configs/api-configs.yaml")
+    api_config = configs["api"]["docker-host"]
+    testcfg = kernelci.api.get_api(api_config)
+    apihelper = APIHelper(testcfg)
+    node = apihelper._fsanitize_node_fields(node, "commit_message")  # pylint: disable=protected-access  # noqa: E501
+    # Test that the _fsanitize_fsanitize_node_fields method returns a dictionary
+    assert isinstance(node, dict)
+    # test that commit message doesnt contain single curly braces
+    # they should be replaced with double curly braces
+    val = node["data"]["kernel_revision"]["commit_message"]
+    assert val == (
+        "x86/its: Fix build errors when CONFIG_MODULES=n\n\n"
+        "Fix several build errors when CONFIG_MODULES=n, including the following:\n\n"
+        "../arch/x86/kernel/alternative.c:195:25: error: incomplete definition of type 'struct module'\n"  # noqa: E501
+        "  195 |         for (int i = 0; i < mod->its_num_pages; i++) {{\n\n"
+        'Fixes: 872df34d7c51 ("x86/its: Use dynamic thunks for indirect branches")\n'
+        "Cc: stable@vger.kernel.org\n"
+        "Signed-off-by: Eric Biggers \n"
+        "Acked-by: Dave Hansen \n"
+        "Tested-by: Steven Rostedt (Google) \n"
+        "Reviewed-by: Alexandre Chartre \n"
+        "Signed-off-by: Linus Torvalds "
+    )