diff --git a/aegisub/src/auto4_lua_dialog.cpp b/aegisub/src/auto4_lua_dialog.cpp
index a8cb5e4e4..6107c4c2a 100644
--- a/aegisub/src/auto4_lua_dialog.cpp
+++ b/aegisub/src/auto4_lua_dialog.cpp
@@ -310,7 +310,11 @@ namespace Automation4 {
 				DoubleValidator(double *value) : value(value) { }
 				wxValidator *Clone() const { return new DoubleValidator(value); }
 				bool Validate(wxWindow*) { return true; }
-				bool TransferToWindow() { return true; }
+
+				bool TransferToWindow() {
+					static_cast<wxSpinCtrlDouble*>(GetWindow())->SetValue(*value);
+					return true;
+				}
 
 				bool TransferFromWindow() {
 					*value = static_cast<wxSpinCtrlDouble*>(GetWindow())->GetValue();