diff --git a/core/include/cib.h b/core/include/cib.h
index 70702d1b6e..1e9e725c03 100644
--- a/core/include/cib.h
+++ b/core/include/cib.h
@@ -86,6 +86,22 @@ static inline int cib_get(cib_t *__restrict cib)
     return -1;
 }
 
+/**
+ * @brief Get the index of the next item in buffer without removing it.
+ *
+ * @param[in,out] cib   corresponding *cib* to buffer.
+ *                      Must not be NULL.
+ * @return index of next item, -1 if the buffer is empty
+ */
+static inline int cib_peek(cib_t *__restrict cib)
+{
+    if (cib->write_count > cib->read_count) {
+        return (int) (cib->read_count & cib->mask);
+    }
+
+    return -1;
+}
+
 /**
  * @brief Get index for item in buffer to put to.
  *
diff --git a/tests/unittests/tests-core/tests-core-cib.c b/tests/unittests/tests-core/tests-core-cib.c
index 7842652506..8991cdaab7 100644
--- a/tests/unittests/tests-core/tests-core-cib.c
+++ b/tests/unittests/tests-core/tests-core-cib.c
@@ -36,6 +36,20 @@ static void test_cib_get(void)
     TEST_ASSERT_EQUAL_INT(-1, cib_get(&cib));
 }
 
+static void test_cib_peek(void)
+{
+    cib_init(&cib, TEST_CIB_SIZE);
+    TEST_ASSERT_EQUAL_INT(-1, cib_peek(&cib));
+    TEST_ASSERT_EQUAL_INT(0, cib_put(&cib));
+    TEST_ASSERT_EQUAL_INT(0, cib_peek(&cib));
+    TEST_ASSERT_EQUAL_INT(1, cib_put(&cib));
+    TEST_ASSERT_EQUAL_INT(0, cib_peek(&cib));
+    TEST_ASSERT_EQUAL_INT(0, cib_get(&cib));
+    TEST_ASSERT_EQUAL_INT(1, cib_peek(&cib));
+    TEST_ASSERT_EQUAL_INT(1, cib_get(&cib));
+    TEST_ASSERT_EQUAL_INT(-1, cib_peek(&cib));
+}
+
 static void test_cib_avail(void)
 {
     TEST_ASSERT_EQUAL_INT(0, cib_avail(&cib));
@@ -83,6 +97,7 @@ Test *tests_core_cib_tests(void)
         new_TestFixture(test_cib_put_and_get),
         new_TestFixture(test_empty_cib),
         new_TestFixture(test_singleton_cib),
+        new_TestFixture(test_cib_peek),
     };
 
     EMB_UNIT_TESTCALLER(core_cib_tests, set_up, NULL, fixtures);