diff --git a/app/src/main/java/org/solovyev/android/calculator/FloatingCalculatorKeyboard.java b/app/src/main/java/org/solovyev/android/calculator/FloatingCalculatorKeyboard.java
index bffff88a..9306bd9e 100644
--- a/app/src/main/java/org/solovyev/android/calculator/FloatingCalculatorKeyboard.java
+++ b/app/src/main/java/org/solovyev/android/calculator/FloatingCalculatorKeyboard.java
@@ -172,6 +172,7 @@ public class FloatingCalculatorKeyboard extends BaseFloatingKeyboard {
 
         @Override
         public void onClick(@NonNull View v) {
+            v.performHapticFeedback(HapticFeedbackConstants.KEYBOARD_TAP);
             switch (v.getId()) {
                 case R.id.cpp_kb_button_divide:
                     user.insertOperator('/');
@@ -215,7 +216,6 @@ public class FloatingCalculatorKeyboard extends BaseFloatingKeyboard {
                     break;
             }
             user.getEditor().requestFocus();
-            v.performHapticFeedback(HapticFeedbackConstants.KEYBOARD_TAP);
         }
 
         private void onDefaultClick(@NonNull View v) {
diff --git a/app/src/main/java/org/solovyev/android/calculator/functions/FunctionsActivity.java b/app/src/main/java/org/solovyev/android/calculator/functions/FunctionsActivity.java
index 0676e2a4..0e1cc0ff 100644
--- a/app/src/main/java/org/solovyev/android/calculator/functions/FunctionsActivity.java
+++ b/app/src/main/java/org/solovyev/android/calculator/functions/FunctionsActivity.java
@@ -52,7 +52,9 @@ public class FunctionsActivity extends BaseActivity {
         if (savedInstanceState == null) {
             final Bundle extras = getIntent().getExtras();
             final CppFunction function = extras != null ? (CppFunction) extras.getParcelable(EXTRA_FUNCTION) : null;
-            EditFunctionFragment.showDialog(function, this);
+            if (function != null) {
+                EditFunctionFragment.showDialog(function, this);
+            }
         }
     }
 
diff --git a/app/src/main/java/org/solovyev/android/calculator/variables/GreekFloatingKeyboard.java b/app/src/main/java/org/solovyev/android/calculator/variables/GreekFloatingKeyboard.java
index b15e610a..62515e36 100644
--- a/app/src/main/java/org/solovyev/android/calculator/variables/GreekFloatingKeyboard.java
+++ b/app/src/main/java/org/solovyev/android/calculator/variables/GreekFloatingKeyboard.java
@@ -118,6 +118,7 @@ public class GreekFloatingKeyboard extends BaseFloatingKeyboard implements View.
 
     @Override
     public void onClick(View v) {
+        v.performHapticFeedback(HapticFeedbackConstants.KEYBOARD_TAP);
         switch (v.getId()) {
             case R.id.cpp_kb_button_close:
                 user.done();
@@ -137,7 +138,6 @@ public class GreekFloatingKeyboard extends BaseFloatingKeyboard implements View.
                 break;
         }
         user.getEditor().requestFocus();
-        v.performHapticFeedback(HapticFeedbackConstants.KEYBOARD_TAP);
     }
 
     private void changeCase(@NonNull Button button) {
diff --git a/app/src/main/java/org/solovyev/android/calculator/variables/VariablesActivity.java b/app/src/main/java/org/solovyev/android/calculator/variables/VariablesActivity.java
index 73ed8b11..f80b5497 100644
--- a/app/src/main/java/org/solovyev/android/calculator/variables/VariablesActivity.java
+++ b/app/src/main/java/org/solovyev/android/calculator/variables/VariablesActivity.java
@@ -49,7 +49,9 @@ public class VariablesActivity extends BaseActivity implements CalculatorEventLi
         if (savedInstanceState == null) {
             final Bundle extras = getIntent().getExtras();
             final CppVariable variable = extras != null ? (CppVariable) extras.getParcelable(EXTRA_VARIABLE) : null;
-            EditVariableFragment.showDialog(variable, this);
+            if (variable != null) {
+                EditVariableFragment.showDialog(variable, this);
+            }
         }
     }