diff --git a/test/testother.cpp b/test/testother.cpp
index 7d34ade72..1ce4c4105 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -6113,10 +6113,19 @@ private:
         ASSERT_EQUALS("[test.cpp:2]: (error) Expression '++exp,(char**)&exp' depends on order of evaluation of side effects\n", errout.str());
 
         // sequence points
-        check("void f(int id) {\n"
-              "  id = dostuff(id += 42);\n"
-              "}");
-        ASSERT_EQUALS("", errout.str());
+        {
+            // FP
+            check("void f(int id) {\n"
+                  "  id = dostuff(id += 42);\n"
+                  "}");
+            ASSERT_EQUALS("", errout.str());
+
+            // FN
+            check("void f(int id) {\n"
+                  "  id = id + dostuff(id += 42);\n"
+                  "}");
+            TODO_ASSERT_EQUALS("error", "", errout.str());
+        }
     }
 };