diff --git a/src/include/daos_srv/dlck.h b/src/include/daos_srv/dlck.h
index f7ef07eccbd..4f708fd7843 100644
--- a/src/include/daos_srv/dlck.h
+++ b/src/include/daos_srv/dlck.h
@@ -8,6 +8,7 @@
 #define __DAOS_DLCK_H__
 
 #include "d_vector.h"
+#include "dlck_debug.h"
 
 /**
  * Trace a single DTX record.
@@ -70,12 +71,6 @@ dlck_dtx_act_recs_remove(daos_handle_t coh);
 int
 dlck_dtx_act_recs_set(daos_handle_t coh, d_vector_t *dv);
 
-#ifdef DLCK_UT_BUILD
-#define DLCK_STATIC
-#else
-#define DLCK_STATIC static
-#endif
-
 /**
  * \struct dlck_iter_bundle
  *
diff --git a/src/include/daos_srv/dlck_debug.h b/src/include/daos_srv/dlck_debug.h
new file mode 100644
index 00000000000..12f9a5d26cc
--- /dev/null
+++ b/src/include/daos_srv/dlck_debug.h
@@ -0,0 +1,16 @@
+/**
+ * (C) Copyright 2025 Hewlett Packard Enterprise Development LP
+ *
+ * SPDX-License-Identifier: BSD-2-Clause-Patent
+ */
+
+#ifndef __DLCK_DEBUG_H__
+#define __DLCK_DEBUG_H__
+
+#ifdef DLCK_UT_BUILD
+#define DLCK_STATIC
+#else
+#define DLCK_STATIC static
+#endif
+
+#endif /** __DLCK_DEBUG_H__ */
diff --git a/src/utils/dlck/dlck_args_files.c b/src/utils/dlck/dlck_args_files.c
index c6814759cad..d1b5eb9186c 100644
--- a/src/utils/dlck/dlck_args_files.c
+++ b/src/utils/dlck/dlck_args_files.c
@@ -11,13 +11,14 @@
 #include <gurt/list.h>
 
 #include "dlck_args.h"
+#include "daos_srv/dlck_debug.h"
 
 static struct argp_option args_files_options[] = {
     {"file", KEY_FILES, "UUID,TARGET", 0,
      "Pool UUID and set of targets. Can be used more than once.", GROUP_OPTIONS},
     {0}};
 
-static void
+DLCK_STATIC void
 args_files_init(struct dlck_args_files *args)
 {
 	memset(args, 0, sizeof(*args));
@@ -25,7 +26,7 @@ args_files_init(struct dlck_args_files *args)
 	D_INIT_LIST_HEAD(&args->list);
 }
 
-static int
+DLCK_STATIC int
 args_files_check(struct argp_state *state, struct dlck_args_files *args)
 {
 	if (d_list_empty(&args->list)) {
diff --git a/src/utils/dlck/tests/SConscript b/src/utils/dlck/tests/SConscript
index 2e9db925b6c..d3db6b6a20c 100644
--- a/src/utils/dlck/tests/SConscript
+++ b/src/utils/dlck/tests/SConscript
@@ -55,6 +55,20 @@ def build_dlck_vos_cont_recs_get_active(venv):
     venv.Install('$PREFIX/bin/', program)
 
 
+def build_dlck_args_files_ut(venv):
+    """Build dlck_args_files.c test"""
+    venv.require('cmocka')
+    venv.AppendUnique(LINKFLAGS=['-Wl,--wrap=argp_failure'])
+    venv.AppendUnique(LINKFLAGS=['-Wl,--wrap=d_calloc'])
+    venv.AppendUnique(LINKFLAGS=['-Wl,--wrap=d_free'])
+    libs = ['cmocka', 'gurt', 'daos_common_pmem', 'uuid']
+    srcs = ['dlck_args_files_ut.c', '../dlck_args_files.c']
+    cppdefines = ['DLCK_UT_BUILD']
+
+    program = venv.d_test_program('dlck_args_files_ut', srcs, LIBS=libs, CPPDEFINES=cppdefines)
+    venv.Install('$PREFIX/bin/', program)
+
+
 def build_dlck_test_helper(henv):
     """Build dlck_test_helper"""
     henv.Append(OBJPREFIX="dlck_ut_helper_")
@@ -94,6 +108,7 @@ def scons():
     build_dlck_dtx_act_recs_recover_ut(env.Clone())
     build_dlck_vos_cont_recs_get_active(env.Clone())
     build_dlck_test_helper(env.Clone())
+    build_dlck_args_files_ut(env.Clone())
 
 
 if __name__ == "SCons.Script":
diff --git a/src/utils/dlck/tests/dlck_args_files_ut.c b/src/utils/dlck/tests/dlck_args_files_ut.c
new file mode 100644
index 00000000000..91109fbcf47
--- /dev/null
+++ b/src/utils/dlck/tests/dlck_args_files_ut.c
@@ -0,0 +1,241 @@
+/**
+ * (C) Copyright 2025 Hewlett Packard Enterprise Development LP
+ *
+ * SPDX-License-Identifier: BSD-2-Clause-Patent
+ */
+
+#include <stdarg.h>
+#include <stddef.h>
+#include <setjmp.h>
+#include <cmocka.h>
+#include <uuid/uuid.h>
+
+#include <argp.h>
+#include <daos/debug.h>
+
+#include "../dlck_args.h"
+
+void
+args_files_init(struct dlck_args_files *args);
+int
+		   args_files_check(struct argp_state *state, struct dlck_args_files *args);
+extern struct argp argp_file;
+
+/** mocks & globals */
+
+struct argp_state  Argp_state;
+#define MOCK_ARGP_STATE (&Argp_state)
+struct dlck_file File;
+#define MOCK_ARG ((void *)0xDEADBEEF)
+struct dlck_args_files Args;
+
+#define MOCK_KEY_UKNOWN 9999
+
+void
+__wrap_argp_failure(struct argp_state *state, int status, int errnum, const char *fmt, ...)
+{
+	assert_ptr_equal(state, MOCK_ARGP_STATE);
+	check_expected(status);
+	check_expected(errnum);
+	assert_non_null(fmt);
+}
+
+int
+parse_file(const char *arg, struct argp_state *state, struct dlck_file **file_ptr)
+{
+	assert_ptr_equal(arg, MOCK_ARG);
+	assert_ptr_equal(state, MOCK_ARGP_STATE);
+	assert_non_null(file_ptr);
+	int rc = mock_type(int);
+	if (rc == 0) {
+		memset(&File, 0, sizeof(File));
+		*file_ptr = &File;
+	}
+	return rc;
+}
+
+void *
+__wrap_d_calloc(size_t count, size_t eltsize)
+{
+	return test_calloc(count, eltsize);
+}
+
+void
+__wrap_d_free(void *ptr)
+{
+	test_free(ptr);
+}
+
+/** setup (no teardown necessary) */
+static int
+setup(void **unused)
+{
+	args_files_init(&Args);
+	Argp_state.input = &Args;
+	return 0;
+}
+
+/** tests */
+
+static void
+test_check_no_files_fail(void **unused)
+{
+	expect_value(__wrap_argp_failure, status, EINVAL);
+	expect_value(__wrap_argp_failure, errnum, EINVAL);
+
+	int rc = args_files_check(MOCK_ARGP_STATE, &Args);
+	assert_int_equal(rc, EINVAL);
+}
+
+static void
+test_check_success(void **unused)
+{
+	d_list_add_tail(&File.link, &Args.list);
+
+	int rc = args_files_check(MOCK_ARGP_STATE, &Args);
+	assert_int_equal(rc, 0);
+}
+
+static void
+test_parser_KEY_INIT(void **unused)
+{
+	memset(&Args, 0xf, sizeof(Args));
+
+	int rc = argp_file.parser(ARGP_KEY_INIT, NULL, &Argp_state);
+	assert_int_equal(rc, 0);
+
+	assert_true(d_list_empty(&Args.list));
+}
+
+static void
+test_parser_KEY_END_without_files_fails(void **unused)
+{
+	expect_value(__wrap_argp_failure, status, EINVAL);
+	expect_value(__wrap_argp_failure, errnum, EINVAL);
+
+	Argp_state.input = &Args;
+	int rc           = argp_file.parser(ARGP_KEY_END, NULL, &Argp_state);
+	assert_int_equal(rc, EINVAL);
+}
+
+static void
+test_parser_KEY_END_with_files_success(void **unused)
+{
+	d_list_add_tail(&File.link, &Args.list);
+
+	int rc = argp_file.parser(ARGP_KEY_END, NULL, &Argp_state);
+
+	assert_int_equal(rc, 0);
+}
+
+static void
+helper_KEY_is_noop(int key)
+{
+	d_list_add_tail(&File.link, &Args.list);
+	int rc = argp_file.parser(key, NULL, &Argp_state);
+	assert_int_equal(rc, 0);
+	assert_false(d_list_empty(&Args.list));
+}
+
+static void
+test_parser_KEY_SUCCESS_is_noop(void **unused)
+{
+	helper_KEY_is_noop(ARGP_KEY_SUCCESS);
+}
+
+static void
+test_parser_KEY_FINI_is_noop(void **unused)
+{
+	helper_KEY_is_noop(ARGP_KEY_FINI);
+}
+
+static void
+test_KEY_FILE_success(void **unused)
+{
+	will_return(parse_file, 0);
+
+	int rc = argp_file.parser(KEY_FILES, MOCK_ARG, &Argp_state);
+	assert_int_equal(rc, 0);
+
+	assert_false(d_list_empty(&Args.list));
+
+	struct dlck_file *file = d_list_entry(Args.list.next, struct dlck_file, link);
+	assert_ptr_equal(file, &File);
+}
+
+static void
+test_KEY_FILE_fail(void **unused)
+{
+	will_return(parse_file, EINVAL);
+
+	int rc = argp_file.parser(KEY_FILES, MOCK_ARG, &Argp_state);
+	assert_int_equal(rc, EINVAL);
+	assert_true(d_list_empty(&Args.list));
+}
+
+static void
+test_KEY_UNKNOWN_fail(void **unused)
+{
+	int rc = argp_file.parser(MOCK_KEY_UKNOWN, NULL, &Argp_state);
+	assert_int_equal(rc, ARGP_ERR_UNKNOWN);
+}
+
+static void
+test_files_free_empty_list(void **unused)
+{
+	assert_true(d_list_empty(&Args.list));
+	dlck_args_files_free(&Args);
+	assert_true(d_list_empty(&Args.list));
+}
+
+static void
+helper_files_free(int file_num)
+{
+	for (int i = 0; i < file_num; i++) {
+		struct dlck_file *file;
+		D_ALLOC_PTR(file);
+		d_list_add_tail(&file->link, &Args.list);
+	}
+
+	dlck_args_files_free(&Args);
+	assert_true(d_list_empty(&Args.list));
+}
+
+static void
+test_files_free_one_file(void **unused)
+{
+	helper_files_free(1);
+}
+
+static void
+test_files_free_three_files(void **state)
+{
+	helper_files_free(3);
+}
+
+static const struct CMUnitTest tests_all[] = {
+    {"ARGFILES100: args_files_check() no files", test_check_no_files_fail, setup, NULL},
+    {"ARGFILES101: args_files_check() success", test_check_success, setup, NULL},
+    {"ARGFILES102: parser ARGP_KEY_INIT", test_parser_KEY_INIT, setup, NULL},
+    {"ARGFILES103: parser ARGP_KEY_END no files", test_parser_KEY_END_without_files_fails, setup,
+     NULL},
+    {"ARGFILES104: parser ARGP_KEY_END success", test_parser_KEY_END_with_files_success, setup,
+     NULL},
+    {"ARGFILES105: parser ARGP_KEY_SUCCESS noop", test_parser_KEY_SUCCESS_is_noop, setup, NULL},
+    {"ARGFILES106: parser ARGP_KEY_FINI noop", test_parser_KEY_FINI_is_noop, setup, NULL},
+    {"ARGFILES107: KEY_FILES success", test_KEY_FILE_success, setup, NULL},
+    {"ARGFILES108: KEY_FILES fail", test_KEY_FILE_fail, setup, NULL},
+    {"ARGFILES109: unknown key", test_KEY_UNKNOWN_fail, setup, NULL},
+    {"ARGFILES110: dlck_args_files_free() no files", test_files_free_empty_list, setup, NULL},
+    {"ARGFILES111: dlck_args_files_free() one file", test_files_free_one_file, setup, NULL},
+    {"ARGFILES112: dlck_args_files_free() multiple files", test_files_free_three_files, setup,
+     NULL},
+};
+
+int
+main(void)
+{
+	const char *test_name = "dlck_args_files.c tests";
+
+	return cmocka_run_group_tests_name(test_name, tests_all, NULL, NULL);
+}