diff --git a/Core/GDCore/Project/Variable.cpp b/Core/GDCore/Project/Variable.cpp
index 2f06d240be74..4b2b99af57b9 100644
--- a/Core/GDCore/Project/Variable.cpp
+++ b/Core/GDCore/Project/Variable.cpp
@@ -306,7 +306,7 @@ void Variable::UnserializeFrom(const SerializerElement& element) {
 
   if (IsPrimitive(type)) {
     if (type == Type::String) {
-      SetString(element.GetStringAttribute("value", "0", "Value"));
+      SetString(element.GetStringAttribute("value", "", "Value"));
     } else if (type == Type::Number) {
       SetValue(element.GetDoubleAttribute("value", 0.0, "Value"));
     } else if (type == Type::Boolean) {
diff --git a/GDJS/Runtime/variable.ts b/GDJS/Runtime/variable.ts
index 68d58e15bd82..ae1bb2597d41 100644
--- a/GDJS/Runtime/variable.ts
+++ b/GDJS/Runtime/variable.ts
@@ -54,7 +54,7 @@ namespace gdjs {
           // Protect against NaN.
           if (this._value !== this._value) this._value = 0;
         } else if (this._type === 'string') {
-          this._str = '' + varData.value || '0';
+          this._str = varData.value !== undefined ? '' + varData.value : '';
         } else if (this._type === 'boolean') {
           this._bool = !!varData.value;
         } else if (this._type === 'structure') {
diff --git a/newIDE/app/src/VariablesList/VariablesList.js b/newIDE/app/src/VariablesList/VariablesList.js
index 9de67b2d88fc..5de1bfb445a4 100644
--- a/newIDE/app/src/VariablesList/VariablesList.js
+++ b/newIDE/app/src/VariablesList/VariablesList.js
@@ -1885,7 +1885,16 @@ const VariablesList: React.ComponentType<{
         props.variablesContainer
       );
       if (!variable) return;
+      const oldType = variable.getType();
       variable.castTo(newType);
+      // When changing type to String, reset to an empty string.
+      if (newType === 'string' && oldType === gd.Variable.Number) {
+        variable.setString('');
+      }
+      // When changing type to Number, reset to 0.
+      if (newType === 'number' && oldType === gd.Variable.String) {
+        variable.setValue(0);
+      }
       _onChange();
       forceUpdate();
     },