diff --git a/src/Mod/Spreadsheet/App/Expression.h b/src/Mod/Spreadsheet/App/Expression.h
index 51faa9239..7d709fff4 100644
--- a/src/Mod/Spreadsheet/App/Expression.h
+++ b/src/Mod/Spreadsheet/App/Expression.h
@@ -126,8 +126,7 @@ public:
 
     const std::string & getPropertyName() const { return components[propertyIndex].component; }
 
-    const Component & getPropertyComponent(int i) const { assert(i >=0 && i < components.size()); return components[propertyIndex + i]; }
-
+    const Component & getPropertyComponent(std::size_t i) const { assert(i < components.size()); return components[propertyIndex + i]; }
     const std::string & getSubComponent(int i) const { assert(i >= 1); return components[propertyIndex - 1].component; }
 
     std::string getSubPathStr() const;