diff --git a/include/srtp.hh b/include/srtp.hh
index 0bf16fe..259fecf 100644
--- a/include/srtp.hh
+++ b/include/srtp.hh
@@ -112,7 +112,7 @@ namespace uvg_rtp {
              * Return RTP_OK if SRTP setup was successful
              * Return RTP_INVALID_VALUE if "zrtp" is nullptr
              * Return RTP_MEMORY allocation failed */
-            rtp_error_t init_zrtp(int type, bool use_null_cipher, uvg_rtp::rtp *rtp, uvg_rtp::zrtp *zrtp);
+            rtp_error_t init_zrtp(int type, int flags, uvg_rtp::rtp *rtp, uvg_rtp::zrtp *zrtp);
 
             /* Setup Secure RTP/RTCP connection using user-managed keys
              *
@@ -122,7 +122,7 @@ namespace uvg_rtp {
              * Return RTP_OK if SRTP setup was successful
              * Return RTP_INVALID_VALUE if "key" or "salt" is nullptr
              * Return RTP_MEMORY allocation failed */
-            rtp_error_t init_user(int type, bool use_null_cipher, uint8_t *key, uint8_t *salt);
+            rtp_error_t init_user(int type, int flags, uint8_t *key, uint8_t *salt);
 
             /* Encrypt the payload of "frame" using the private session key
              *
@@ -168,7 +168,7 @@ namespace uvg_rtp {
             rtp_error_t __encrypt(uint32_t ssrc, uint16_t seq, uint8_t *buffer, size_t len);
 
             /* Internal init method that initialize the SRTP context using values in key_ctx_.master */
-            rtp_error_t __init(int type, bool use_null_cipher);
+            rtp_error_t __init(int type, int flags);
 #endif
 
             srtp_key_ctx_t key_ctx_;
diff --git a/src/media_stream.cc b/src/media_stream.cc
index ac620be..73eb37c 100644
--- a/src/media_stream.cc
+++ b/src/media_stream.cc
@@ -12,7 +12,6 @@
 
 #define RECV_ONLY(flags)   ((flags & RECV_ONLY_FLAGS) == RECV_ONLY_FLAGS)
 #define SEND_ONLY(flags)   ((flags & SEND_ONLY_FLAGS) == SEND_ONLY_FLAGS)
-#define NULL_CHIPER(flags) ((flags & RCE_SRTP_USE_NULL_CIPHER) == RCE_SRTP_USE_NULL_CIPHER)
 
 uvg_rtp::media_stream::media_stream(std::string addr, int src_port, int dst_port, rtp_format_t fmt, int flags):
     srtp_(nullptr),
@@ -174,7 +173,7 @@ rtp_error_t uvg_rtp::media_stream::init(uvg_rtp::zrtp *zrtp)
     if ((srtp_ = new uvg_rtp::srtp()) == nullptr)
         return RTP_MEMORY_ERROR;
 
-    if ((ret = srtp_->init_zrtp(SRTP, NULL_CHIPER(ctx_config_.flags), rtp_, zrtp)) != RTP_OK) {
+    if ((ret = srtp_->init_zrtp(SRTP, ctx_config_.flags, rtp_, zrtp)) != RTP_OK) {
         LOG_WARN("Failed to initialize SRTP for media stream!");
         return ret;
     }
@@ -214,7 +213,7 @@ rtp_error_t uvg_rtp::media_stream::add_srtp_ctx(uint8_t *key, uint8_t *salt)
     if ((srtp_ = new uvg_rtp::srtp()) == nullptr)
         return RTP_MEMORY_ERROR;
 
-    if ((ret = srtp_->init_user(SRTP, NULL_CHIPER(ctx_config_.flags), key, salt)) != RTP_OK) {
+    if ((ret = srtp_->init_user(SRTP, ctx_config_.flags, key, salt)) != RTP_OK) {
         LOG_WARN("Failed to initialize SRTP for media stream!");
         return ret;
     }
diff --git a/src/srtp.cc b/src/srtp.cc
index c6ecaac..cbf0ed5 100644
--- a/src/srtp.cc
+++ b/src/srtp.cc
@@ -54,7 +54,7 @@ rtp_error_t uvg_rtp::srtp::create_iv(uint8_t *out, uint32_t ssrc, uint64_t index
     return RTP_OK;
 }
 
-rtp_error_t uvg_rtp::srtp::__init(int type, bool use_null_cipher)
+rtp_error_t uvg_rtp::srtp::__init(int type, int flags)
 {
     srtp_ctx_.roc  = 0;
     srtp_ctx_.type = type;
@@ -75,7 +75,7 @@ rtp_error_t uvg_rtp::srtp::__init(int type, bool use_null_cipher)
     srtp_ctx_.s_l    = 0;
     srtp_ctx_.replay = nullptr;
 
-    use_null_cipher_ = use_null_cipher;
+    use_null_cipher_  = !!(flags & RCE_SRTP_NULL_CIPHER);
 
     /* Local aka encryption keys */
     (void)derive_key(
@@ -126,7 +126,7 @@ rtp_error_t uvg_rtp::srtp::__init(int type, bool use_null_cipher)
     return RTP_OK;
 }
 
-rtp_error_t uvg_rtp::srtp::init_zrtp(int type, bool use_null_cipher, uvg_rtp::rtp *rtp, uvg_rtp::zrtp *zrtp)
+rtp_error_t uvg_rtp::srtp::init_zrtp(int type, int flags, uvg_rtp::rtp *rtp, uvg_rtp::zrtp *zrtp)
 {
     (void)rtp;
 
@@ -151,10 +151,10 @@ rtp_error_t uvg_rtp::srtp::init_zrtp(int type, bool use_null_cipher, uvg_rtp::rt
         return ret;
     }
 
-    return __init(type, use_null_cipher);
+    return __init(type, flags);
 }
 
-rtp_error_t uvg_rtp::srtp::init_user(int type, bool use_null_cipher, uint8_t *key, uint8_t *salt)
+rtp_error_t uvg_rtp::srtp::init_user(int type, int flags, uint8_t *key, uint8_t *salt)
 {
     if (!key || !salt)
         return RTP_INVALID_VALUE;
@@ -164,7 +164,7 @@ rtp_error_t uvg_rtp::srtp::init_user(int type, bool use_null_cipher, uint8_t *ke
     memcpy(key_ctx_.master.local_salt,  salt, SALT_LENGTH);
     memcpy(key_ctx_.master.remote_salt, salt, SALT_LENGTH);
 
-    return __init(type, use_null_cipher);
+    return __init(type, flags);
 }
 
 rtp_error_t uvg_rtp::srtp::__encrypt(uint32_t ssrc, uint16_t seq, uint8_t *buffer, size_t len)