diff --git a/cf-net/cf-net.c b/cf-net/cf-net.c
index aaf8c7f4d23..10badcc1754 100644
--- a/cf-net/cf-net.c
+++ b/cf-net/cf-net.c
@@ -133,7 +133,7 @@ static const char *const HINTS[] =
     "Enable basic information output",
     "Minimum TLS version to use",
     "TLS ciphers to use (comma-separated list)",
-    "Specify CFEngine protocol to use. Possible values: 'classic', 'tls', 'cookie', 'filestream', 'leech2', 'latest' (default)",
+    "Specify CFEngine protocol to use. Possible values: 'classic', 'tls', 'cookie', 'filestream', 'leech2', 'transfusion', 'latest' (default)",
     "Print rsync performance statistics to stderr",
     NULL
 };
diff --git a/libcfnet/protocol_version.c b/libcfnet/protocol_version.c
index 56049c582c4..034f01be582 100644
--- a/libcfnet/protocol_version.c
+++ b/libcfnet/protocol_version.c
@@ -41,6 +41,10 @@ ProtocolVersion ParseProtocolVersionPolicy(const char *const s)
     {
         return CF_PROTOCOL_LEECH2;
     }
+    else if (StringEqual(s, "6") || StringEqual(s, "transfusion"))
+    {
+        return CF_PROTOCOL_TRANSFUSION;
+    }
     else if (StringEqual(s, "latest"))
     {
         return CF_PROTOCOL_LATEST;
diff --git a/libcfnet/protocol_version.h b/libcfnet/protocol_version.h
index 14d90303056..9ca344e019f 100644
--- a/libcfnet/protocol_version.h
+++ b/libcfnet/protocol_version.h
@@ -41,10 +41,11 @@ typedef enum
     CF_PROTOCOL_COOKIE = 3,
     CF_PROTOCOL_FILESTREAM = 4,
     CF_PROTOCOL_LEECH2 = 5,
+    CF_PROTOCOL_TRANSFUSION = 6,
 } ProtocolVersion;
 
 /* We use CF_PROTOCOL_LATEST as the default for new connections. */
-#define CF_PROTOCOL_LATEST CF_PROTOCOL_LEECH2
+#define CF_PROTOCOL_LATEST CF_PROTOCOL_TRANSFUSION
 
 static inline const char *ProtocolVersionString(const ProtocolVersion p)
 {
@@ -60,6 +61,8 @@ static inline const char *ProtocolVersionString(const ProtocolVersion p)
         return "filestream";
     case CF_PROTOCOL_LEECH2:
         return "leech2";
+    case CF_PROTOCOL_TRANSFUSION:
+        return "transfusion";
     default:
         return "undefined";
     }
@@ -100,6 +103,11 @@ static inline bool ProtocolSupportsLeech2(const ProtocolVersion p)
     return (p >= CF_PROTOCOL_LEECH2);
 }
 
+static inline bool ProtocolSupportsTransfusion(const ProtocolVersion p)
+{
+    return (p >= CF_PROTOCOL_TRANSFUSION);
+}
+
 static inline bool ProtocolTerminateCSV(const ProtocolVersion p)
 {
     return (p < CF_PROTOCOL_COOKIE);
diff --git a/libpromises/mod_common.c b/libpromises/mod_common.c
index b3ce69ae73a..706b072f937 100644
--- a/libpromises/mod_common.c
+++ b/libpromises/mod_common.c
@@ -266,7 +266,7 @@ const ConstraintSyntax CFG_CONTROLBODY[COMMON_CONTROL_MAX + 1] =
     ConstraintSyntaxNewBool("fips_mode", "Activate full FIPS mode restrictions. Default value: false", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewReal("bwlimit", CF_VALRANGE, "Limit outgoing protocol bandwidth in Bytes per second", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewBool("cache_system_functions", "Cache the result of system functions. Default value: true", SYNTAX_STATUS_NORMAL),
-    ConstraintSyntaxNewOption("protocol_version", "1,classic,2,tls,3,cookie,4,filestream,5,leech2,latest", "CFEngine protocol version to use when connecting to the server. Default: \"latest\"", SYNTAX_STATUS_NORMAL),
+    ConstraintSyntaxNewOption("protocol_version", "1,classic,2,tls,3,cookie,4,filestream,5,leech2,6,transfusion,latest", "CFEngine protocol version to use when connecting to the server. Default: \"latest\"", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewString("tls_ciphers", "", "List of acceptable ciphers in outgoing TLS connections, defaults to OpenSSL's default. For syntax help see man page for \"openssl ciphers\"", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewString("tls_min_version", "", "Minimum acceptable TLS version for outgoing connections, defaults to OpenSSL's default", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewStringList("package_inventory", ".*", "Name of the package manager used for software inventory management", SYNTAX_STATUS_NORMAL),
diff --git a/libpromises/mod_files.c b/libpromises/mod_files.c
index fc93b4b155d..8ea14d6bfb1 100644
--- a/libpromises/mod_files.c
+++ b/libpromises/mod_files.c
@@ -336,7 +336,7 @@ static const ConstraintSyntax copy_from_constraints[] =
     ConstraintSyntaxNewBool("trustkey", "true/false trust public keys from remote server if previously unknown. Default value: false", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewBool("type_check", "true/false compare file types before copying and require match", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewBool("verify", "true/false verify transferred file by hashing after copy (resource penalty). Default value: false", SYNTAX_STATUS_NORMAL),
-    ConstraintSyntaxNewOption("protocol_version", "1,classic,2,tls,3,cookie,4,filestream,5,leech2,latest", "CFEngine protocol version to use when connecting to the server. Default: undefined", SYNTAX_STATUS_NORMAL),
+    ConstraintSyntaxNewOption("protocol_version", "1,classic,2,tls,3,cookie,4,filestream,5,leech2,6,transfusion,latest", "CFEngine protocol version to use when connecting to the server. Default: undefined", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewBool("missing_ok", "true/false Do not treat missing file as an error. Default value: false", SYNTAX_STATUS_NORMAL),
     ConstraintSyntaxNewNull()
 };