diff --git a/sys/include/xtimer.h b/sys/include/xtimer.h
index 30ecf5cdae..c6997f329e 100644
--- a/sys/include/xtimer.h
+++ b/sys/include/xtimer.h
@@ -37,6 +37,7 @@
 #endif /* MODULE_CORE_MSG */
 #include "mutex.h"
 #include "kernel_types.h"
+#include "rmutex.h"
 
 #ifdef MODULE_ZTIMER_XTIMER_COMPAT
 #include "ztimer/xtimer_compat.h"
@@ -413,7 +414,19 @@ static inline bool xtimer_less64(xtimer_ticks64_t a, xtimer_ticks64_t b);
  */
 int xtimer_mutex_lock_timeout(mutex_t *mutex, uint64_t us);
 
+/**
+ * @brief lock a rmutex but with timeout
+ *
+ * @param[in]    rmutex  rmutex to lock
+ * @param[in]    us     timeout in microseconds relative
+ *
+ * @return       0, when returned after rmutex was locked
+ * @return       -1, when the timeout occcured
+ */
+int xtimer_rmutex_lock_timeout(rmutex_t *rmutex, uint64_t us);
+
 #if defined(MODULE_CORE_THREAD_FLAGS) || defined(DOXYGEN)
+
 /**
  * @brief    Set timeout thread flag after @p timeout
  *