diff --git a/app/src/androidTest/java/org/solovyev/android/calculator/plot/PlotEditFunctionFragmentTest.java b/app/src/androidTest/java/org/solovyev/android/calculator/plot/PlotEditFunctionFragmentTest.java
index 235dcdde..c49ea058 100644
--- a/app/src/androidTest/java/org/solovyev/android/calculator/plot/PlotEditFunctionFragmentTest.java
+++ b/app/src/androidTest/java/org/solovyev/android/calculator/plot/PlotEditFunctionFragmentTest.java
@@ -5,9 +5,12 @@ import org.solovyev.android.calculator.R;
 import org.solovyev.android.calculator.functions.CppFunction;
 
 import static android.support.test.espresso.Espresso.onView;
+import static android.support.test.espresso.action.ViewActions.click;
 import static android.support.test.espresso.assertion.ViewAssertions.matches;
+import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
 import static android.support.test.espresso.matcher.ViewMatchers.withId;
 import static android.support.test.espresso.matcher.ViewMatchers.withText;
+import static org.hamcrest.Matchers.not;
 
 public class PlotEditFunctionFragmentTest extends BasePlotTest {
 
@@ -19,4 +22,17 @@ public class PlotEditFunctionFragmentTest extends BasePlotTest {
         openFunctionsList();
         onView(withId(R.id.function_name)).check(matches(withText("x+y")));
     }
+
+    @Test
+    public void testShouldHaveOnlyTwoParameters() throws Exception {
+        openFunctionEditor();
+
+        onView(withId(R.id.function_params_add)).check(matches(isDisplayed()));
+
+        onView(withId(R.id.function_params_add)).perform(click());
+        onView(withId(R.id.function_params_add)).check(matches(isDisplayed()));
+        onView(withId(R.id.function_params_add)).perform(click());
+
+        onView(withId(R.id.function_params_add)).check(matches(not(isDisplayed())));
+    }
 }
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