diff --git a/include/client.h b/include/client.h
index 4a28a307..e145aa54 100644
--- a/include/client.h
+++ b/include/client.h
@@ -443,6 +443,7 @@ struct ListClient
 
 #define CLICAP_MULTI_PREFIX	0x0001
 #define CLICAP_SASL		0x0002
+#define CLICAP_ACCOUNT_HOSTMASK	0x0004
 
 /*
  * flags macros.
diff --git a/modules/m_cap.c b/modules/m_cap.c
index 94aebaca..c5283a8c 100644
--- a/modules/m_cap.c
+++ b/modules/m_cap.c
@@ -69,7 +69,8 @@ static struct clicap
 	int namelen;
 } clicap_list[] = {
 	_CLICAP("multi-prefix",	CLICAP_MULTI_PREFIX, 0, 0),
-	_CLICAP("sasl", CLICAP_SASL, 0, 0)
+	_CLICAP("sasl", CLICAP_SASL, 0, 0),
+	_CLICAP("source-account-hostmask", CLICAP_ACCOUNT_HOSTMASK, 0, 0),
 };
 
 #define CLICAP_LIST_LEN (sizeof(clicap_list) / sizeof(struct clicap))