diff --git a/src/debugger/gui/RomListWidget.cxx b/src/debugger/gui/RomListWidget.cxx
index 504f7443d..0d0d6c3fa 100644
--- a/src/debugger/gui/RomListWidget.cxx
+++ b/src/debugger/gui/RomListWidget.cxx
@@ -472,7 +472,7 @@ string RomListWidget::getToolTip(Common::Point pos) const
   if(bytes.length() == 8 && bytes[2] != ' ')
   {
     // Binary value
-    val = static_cast<Int32>(stol(bytes, 0, 2));
+    val = static_cast<Int32>(stol(bytes, nullptr, 2));
   }
   else
   {
@@ -484,7 +484,7 @@ string RomListWidget::getToolTip(Common::Point pos) const
     // Get one hex byte
     const string valStr = bytes.substr((idx.x / 3) * 3, 2);
 
-    val = static_cast<Int32>(stol(valStr, 0, 16));
+    val = static_cast<Int32>(stol(valStr, nullptr, 16));
 
   }
   ostringstream buf;