diff --git a/CHANGELOG.md b/CHANGELOG.md
index 61333107d..2332cb2c0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -56,6 +56,7 @@ This project uses the changelog in accordance with [keepchangelog](http://keepac
  - Now `script run hf_mf_ultimatecard.lua -u` supports 10bytes UID (@alejandro12120)
  - Update documentation for installation on macOS with MacPorts (@linuxgemini)
  - Added possible Paxton id to hitag2 tag info output
+ - Changed `hf mf sim` - reduce 50ms threshold to 6ms for reset to idle #1974 (@net147)
 
 ## [Nitride.4.16191][2023-01-29]
  - Changed `build_all_firmwares.sh` to fit GENERIC 256kb firmware images (@doegox)
diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 637215cc3..a8cc1414b 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -2084,8 +2084,8 @@ int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *par) {
                     if (timer == 0) {
                         timer = GetTickCount();
                     } else {
-                        // 50ms no field --> card to idle state
-                        if (GetTickCountDelta(timer) > 50) {
+                        // 6ms no field --> card to idle state
+                        if (GetTickCountDelta(timer) > 6) {
                             return 2;
                         }
                     }