diff --git a/include/nanocbor/nanocbor.h b/include/nanocbor/nanocbor.h
index 6ccf7d1..85aa80d 100644
--- a/include/nanocbor/nanocbor.h
+++ b/include/nanocbor/nanocbor.h
@@ -482,8 +482,11 @@ int nanocbor_enter_map(const nanocbor_value_t *it, nanocbor_value_t *map);
  *
  * @param[in]   it          parent CBOR structure
  * @param[in]   container   exhausted CBOR container
+ *
+ * @return                  NANOCBOR_OK on success
+ * @return                  negative on error
  */
-void nanocbor_leave_container(nanocbor_value_t *it,
+int nanocbor_leave_container(nanocbor_value_t *it,
                               nanocbor_value_t *container);
 
 /**
diff --git a/src/decoder.c b/src/decoder.c
index de06302..5c279bc 100644
--- a/src/decoder.c
+++ b/src/decoder.c
@@ -513,8 +513,15 @@ int nanocbor_enter_map(const nanocbor_value_t *it, nanocbor_value_t *map)
     return res;
 }
 
-void nanocbor_leave_container(nanocbor_value_t *it, nanocbor_value_t *container)
+int nanocbor_leave_container(nanocbor_value_t *it, nanocbor_value_t *container)
 {
+    /* check `container` to be a valid, fully consumed container that is plausible to have been entered from `it` */
+    if (!nanocbor_in_container(container) ||
+        !nanocbor_at_end(container) ||
+        container->cur <= it->cur ||
+        container->cur > it->end) {
+        return NANOCBOR_ERR_INVALID_TYPE;
+    }
     if (it->remaining) {
         it->remaining--;
     }
@@ -524,6 +531,7 @@ void nanocbor_leave_container(nanocbor_value_t *it, nanocbor_value_t *container)
     else {
         it->cur = container->cur;
     }
+    return NANOCBOR_OK;
 }
 
 static int _skip_simple(nanocbor_value_t *it)
diff --git a/tests/automated/test_decoder.c b/tests/automated/test_decoder.c
index 3f156c1..d60c2a1 100644
--- a/tests/automated/test_decoder.c
+++ b/tests/automated/test_decoder.c
@@ -52,7 +52,7 @@ static void test_decode_map(void)
     nanocbor_decoder_init(&val, map_empty, sizeof(map_empty));
     CU_ASSERT_EQUAL(nanocbor_enter_map(&val, &cont), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&cont), true);
-    nanocbor_leave_container(&val, &cont);
+    CU_ASSERT_EQUAL(nanocbor_leave_container(&val, &cont), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&val), true);
 
     /* Init the decoder and verify the decoding of the map elements */
@@ -63,7 +63,7 @@ static void test_decode_map(void)
     CU_ASSERT(nanocbor_get_uint32(&cont, &tmp) > 0);
     CU_ASSERT_EQUAL(tmp, 2);
     CU_ASSERT_EQUAL(nanocbor_at_end(&cont), true);
-    nanocbor_leave_container(&val, &cont);
+    CU_ASSERT_EQUAL(nanocbor_leave_container(&val, &cont), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&val), true);
 
     /* Init the decoder and skip over the empty map */
@@ -89,21 +89,21 @@ static void test_decode_map(void)
     CU_ASSERT_EQUAL(tmp, 3);
     CU_ASSERT_EQUAL(nanocbor_enter_array(&cont, &array), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&array), true);
-    nanocbor_leave_container(&cont, &array);
+    CU_ASSERT_EQUAL(nanocbor_leave_container(&cont, &array), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&cont), false);
 
     CU_ASSERT(nanocbor_get_uint32(&cont, &tmp) > 0);
     CU_ASSERT_EQUAL(tmp, 4);
     CU_ASSERT_EQUAL(nanocbor_enter_array(&cont, &array), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&array), true);
-    nanocbor_leave_container(&cont, &array);
+    CU_ASSERT_EQUAL(nanocbor_leave_container(&cont, &array), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&cont), false);
 
     CU_ASSERT(nanocbor_get_uint32(&cont, &tmp) > 0);
     CU_ASSERT_EQUAL(tmp, 5);
     CU_ASSERT_EQUAL(nanocbor_enter_array(&cont, &array), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&array), true);
-    nanocbor_leave_container(&cont, &array);
+    CU_ASSERT_EQUAL(nanocbor_leave_container(&cont, &array), NANOCBOR_OK);
     CU_ASSERT_EQUAL(nanocbor_at_end(&cont), false);
 
     CU_ASSERT(nanocbor_get_uint32(&cont, &tmp) > 0);