diff --git a/src/CalcManager/UnitConverter.cpp b/src/CalcManager/UnitConverter.cpp
index 08fe85d4..c847179f 100644
--- a/src/CalcManager/UnitConverter.cpp
+++ b/src/CalcManager/UnitConverter.cpp
@@ -882,7 +882,7 @@ void UnitConverter::Calculate()
 
             auto currentDisplayTrimmed = m_currentDisplay;
             TrimString(currentDisplayTrimmed);
-            int currentNumberSignificantDigits = currentDisplayTrimmed.size();
+            int currentNumberSignificantDigits = static_cast<int>(currentDisplayTrimmed.size());
             if (currentDisplayTrimmed.find(L'.') != currentDisplayTrimmed.npos)
                 --currentNumberSignificantDigits;
             if (currentValue < 0)