diff --git a/src/libstrongswan/crypto/proposal/proposal_keywords_static.txt b/src/libstrongswan/crypto/proposal/proposal_keywords_static.txt
index 77dea333a..1e636e897 100644
--- a/src/libstrongswan/crypto/proposal/proposal_keywords_static.txt
+++ b/src/libstrongswan/crypto/proposal/proposal_keywords_static.txt
@@ -79,6 +79,7 @@ aes128gmac,       ENCRYPTION_ALGORITHM, ENCR_NULL_AUTH_AES_GMAC, 128
 aes192gmac,       ENCRYPTION_ALGORITHM, ENCR_NULL_AUTH_AES_GMAC, 192
 aes256gmac,       ENCRYPTION_ALGORITHM, ENCR_NULL_AUTH_AES_GMAC, 256
 chacha20poly1305, ENCRYPTION_ALGORITHM, ENCR_CHACHA20_POLY1305,    0
+chacha20poly1305compat, ENCRYPTION_ALGORITHM, ENCR_CHACHA20_POLY1305, 256
 blowfish,         ENCRYPTION_ALGORITHM, ENCR_BLOWFISH,           128
 blowfish128,      ENCRYPTION_ALGORITHM, ENCR_BLOWFISH,           128
 blowfish192,      ENCRYPTION_ALGORITHM, ENCR_BLOWFISH,           192