diff --git a/scim-wnn/src/scim_wnn_imengine.cpp b/scim-wnn/src/scim_wnn_imengine.cpp
index ca2a2af..c8fd0c4 100644
--- a/scim-wnn/src/scim_wnn_imengine.cpp
+++ b/scim-wnn/src/scim_wnn_imengine.cpp
@@ -210,6 +210,7 @@
         m_rk.backspace();
         update_preedit_string(m_rk.getText());
         update_preedit_caret(m_rk.getPos());
+        return(true);
     }
     if (isprint(key.code)) {
         show_preedit_string();