diff --git a/doc/trex_astf.asciidoc b/doc/trex_astf.asciidoc
index f7352afc4f..d913608c26 100644
--- a/doc/trex_astf.asciidoc
+++ b/doc/trex_astf.asciidoc
@@ -3915,7 +3915,7 @@ link:cp_astf_docs/index.html[python index]
 |   tcp.keepidle    |2-65533|5|-|+| value in second for TCP keepidle
 |   tcp.keepintvl   |2-65533|7|-|+| value in second for TCP keepalive interval
 |   tcp.blackhole   |0,1,2|0|-|+| 0 - return RST packet in case of error. 1- return of RST only in SYN. 2- don't return any RST packet, make a blackhole.
-|   tcp.delay_ack_msec | 20-50000|100|-|+| delay ack timeout in msec.  Reducing this value will reduce the performance but will reduce the active flows
+|   tcp.delay_ack_msec | 1-50000|100|-|+| delay ack timeout in msec.  Reducing this value will reduce the performance but will reduce the active flows
 |   tcp.no_delay    | 0-3   | 0|+|+| 2 bits: LSB - Nagle Algorithm (0 - Enabled, 1 - Disabled). MSB - Force Push (FP) (0 - Disabled, 1 - Enabled).
 |   tcp.no_delay_counter    | 0-65533   | 0|+|+|  number of recv bytes to wait until ack is sent. notice ack can be triggered by tcp timer, in order to ensure fixed number of sent packets until ack you should increase the *tcp.initwnd* tunable. otherwise no_delay_counter will race with the tcp timer.
 |   scheduler.rampup_sec    | 3-60000  | disabled |-|+|  scheduler rampup in seconds. After this time the throughput would be the maximum. the throughput increases linearly every 1 sec.
diff --git a/src/astf/astf_db.cpp b/src/astf/astf_db.cpp
index d4a4467ebc..967656dff7 100644
--- a/src/astf/astf_db.cpp
+++ b/src/astf/astf_db.cpp
@@ -1076,7 +1076,7 @@ bool CAstfDB::read_tunables(CTcpTuneables *tune, Json::Value tune_json) {
             }
 
             if (read_tunable_uint16(tune,json,"delay_ack_msec",CTcpTuneables::tcp_delay_ack,tune->m_tcp_delay_ack_msec)){
-                tunable_min_max_u32("delay_ack_msec",tune->m_tcp_delay_ack_msec,20,50000);
+                tunable_min_max_u32("delay_ack_msec",tune->m_tcp_delay_ack_msec,1,50000);
             }
 
             if (read_tunable_uint16(tune, json, "no_delay_counter", CTcpTuneables::tcp_no_delay_counter,tune->m_tcp_no_delay_counter)){
diff --git a/src/astf/astf_db.h b/src/astf/astf_db.h
index c406d3e08b..09a93ac9c9 100644
--- a/src/astf/astf_db.h
+++ b/src/astf/astf_db.h
@@ -155,7 +155,7 @@ class CTcpTuneables {
     uint16_t  m_tcp_keepinit;
     uint16_t  m_tcp_keepidle;
     uint16_t  m_tcp_keepintvl;
-    uint16_t m_tcp_delay_ack_msec; /* 20-500msec */
+    uint16_t m_tcp_delay_ack_msec; /* 1-500msec */
 
     uint16_t m_tcp_mss;
     uint16_t m_tcp_initwnd; /* init window*/