diff --git a/apps/calculation/calculation.cpp b/apps/calculation/calculation.cpp
index c8c4a2015..316ee529d 100644
--- a/apps/calculation/calculation.cpp
+++ b/apps/calculation/calculation.cpp
@@ -91,7 +91,7 @@ ExpressionLayout * Calculation::outputLayout(Context * context) {
 }
 
 bool Calculation::isEmpty() {
-  if (strlen(m_inputText) == 0) {
+  if (strlen(m_outputText) == 0) {
     return true;
   }
   return false;