diff --git a/AUTHORS b/AUTHORS
index 8e17b65..0c84bf9 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -13,6 +13,7 @@
 Brett Wilson <brettw@chromium.org>
 Bruce Dawson <brucedawson@chromium.org>
 Chery Cherian <cherycherian@gmail.com>
+Claudio DeSouza <claudiomdsjr@gmail.com>
 Chris Palmer <palmer@chromium.org>
 Dan Sinclair <dsinclair@chromium.org>
 Felix Kauselmann <licorn@gmail.com>
diff --git a/fpdfsdk/formfiller/cffl_checkbox.cpp b/fpdfsdk/formfiller/cffl_checkbox.cpp
index 1a3ccca..9691f6d 100644
--- a/fpdfsdk/formfiller/cffl_checkbox.cpp
+++ b/fpdfsdk/formfiller/cffl_checkbox.cpp
@@ -58,9 +58,12 @@
       }
 
       CFFL_FormFiller::OnChar(pAnnot, nChar, nFlags);
+
       CPWL_CheckBox* pWnd = GetCheckBox(pPageView, true);
-      if (pWnd)
-        pWnd->SetCheck(!pWnd->IsChecked());
+      if (pWnd) {
+        CPDFSDK_Widget* pWidget = static_cast<CPDFSDK_Widget*>(pAnnot);
+        pWnd->SetCheck(!pWidget->IsChecked());
+      }
 
       return CommitData(pPageView, nFlags);
     }