diff --git a/reactos/subsys/system/calc/winecalc.c b/reactos/subsys/system/calc/winecalc.c
index e2b8f09f591..529daa8f050 100644
--- a/reactos/subsys/system/calc/winecalc.c
+++ b/reactos/subsys/system/calc/winecalc.c
@@ -3261,6 +3261,7 @@ int parse(int wParam, int lParam)
         calc.next = 1;
         calc.buffer[0] = TEXT('\0');
         calc.value = 0;
+        calc.init = 1;
         break;
 
     case TEXT('0'):