diff --git a/src/rime/gear/charset_filter.cc b/src/rime/gear/charset_filter.cc
index 79185f17d..1cbce26ca 100644
--- a/src/rime/gear/charset_filter.cc
+++ b/src/rime/gear/charset_filter.cc
@@ -25,6 +25,7 @@ bool is_extended_cjk(uint32_t ch)
       (ch >= 0x2B820 && ch <= 0x2CEAF) ||  // CJK Unified Ideographs Extension E
       (ch >= 0x2CEB0 && ch <= 0x2EBEF) ||  // CJK Unified Ideographs Extension F
       (ch >= 0x30000 && ch <= 0x3134F) ||  // CJK Unified Ideographs Extension G
+      (ch >= 0xF900 && ch <= 0xFAFF) ||    // CJK Compatibility Ideographs
       (ch >= 0x2F800 && ch <= 0x2FA1F))    // CJK Compatibility Ideographs Supplement
     return true;