diff --git a/tests/unittests/main.c b/tests/unittests/main.c
index 23399752d5e7..8c6092b80bde 100644
--- a/tests/unittests/main.c
+++ b/tests/unittests/main.c
@@ -31,7 +31,7 @@ int main(void)
     ztimer_init();
 #endif
 
-#ifdef MODULE_XTIMER
+#if IS_USED(MODULE_XTIMER) && !IS_USED(MODULE_ZTIMER_XTIMER_COMPAT)
     /* auto_init is disabled, but some modules depends on this module being initialized */
     xtimer_init();
 #endif
diff --git a/tests/unittests/tests-zt/Makefile b/tests/unittests/tests-zt/Makefile
new file mode 100644
index 000000000000..6c572ed15c17
--- /dev/null
+++ b/tests/unittests/tests-zt/Makefile
@@ -0,0 +1,6 @@
+# avoid clang warning in tests-ztimer/tests-ztimer-extend.c:141
+ifeq (llvm,$(TOOLCHAIN))
+  CFLAGS += -Wno-gnu-folding-constant
+endif
+
+include $(RIOTBASE)/Makefile.base
diff --git a/tests/unittests/tests-zt/Makefile.include b/tests/unittests/tests-zt/Makefile.include
new file mode 100644
index 000000000000..320a2283c268
--- /dev/null
+++ b/tests/unittests/tests-zt/Makefile.include
@@ -0,0 +1,2 @@
+USEMODULE += ztimer_core
+USEMODULE += ztimer_msec
diff --git a/tests/unittests/tests-zt/tests-zt.c b/tests/unittests/tests-zt/tests-zt.c
new file mode 100644
index 000000000000..78fb61e720e9
--- /dev/null
+++ b/tests/unittests/tests-zt/tests-zt.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2022 K F
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @{
+ *
+ * @file
+ * @brief       Unittest entry point for the zt test group
+ *
+ * @author      kfessel
+ */
+#include <stdint.h>
+#include <ztimer.h>
+#include <stdio.h>
+#include "embUnit/embUnit.h"
+
+#include "tests-zt.h"
+
+void zt_sleep(void){
+    uint32_t start = ztimer_now(ZTIMER_MSEC);
+    puts( "will sleep");
+    ztimer_sleep(ZTIMER_MSEC,2000);
+    puts( "done sleep");
+    uint32_t end = ztimer_now(ZTIMER_MSEC);
+    TEST_ASSERT_EQUAL_INT(2000, end - start);
+
+}
+
+Test * tests_zt_test(void){
+
+    EMB_UNIT_TESTFIXTURES(fixtures) {
+        new_TestFixture(zt_sleep)
+    };
+
+    EMB_UNIT_TESTCALLER(zt_tests, NULL, NULL, fixtures);
+
+    return (Test *)&zt_tests;
+}
+
+void tests_zt(void)
+{
+    TESTS_RUN(tests_zt_test());
+
+}
+/** @} */
diff --git a/tests/unittests/tests-zt/tests-zt.h b/tests/unittests/tests-zt/tests-zt.h
new file mode 100644
index 000000000000..1f2718f2893a
--- /dev/null
+++ b/tests/unittests/tests-zt/tests-zt.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2022 K F
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @addtogroup  unittests
+ * @{
+ *
+ * @file
+ * @brief       Unittests for zt
+ *
+ * @author      kfessel
+ */
+#ifndef TESTS_ZT_H
+#define TESTS_ZT_H
+
+#include "embUnit.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief   The entry point of this test suite.
+ */
+void tests_zt(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* TESTS_ZT_H */
+/** @} */