diff --git a/keyboards/aleblazer/zodiark/config.h b/keyboards/aleblazer/zodiark/config.h
index 90ecb7ce96..2958e8daed 100644
--- a/keyboards/aleblazer/zodiark/config.h
+++ b/keyboards/aleblazer/zodiark/config.h
@@ -19,7 +19,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "config_common.h"
 
 #define SOFT_SERIAL_PIN D3
-#define SERIAL_USE_MULTI_TRANSACTION
 #define SELECT_SOFT_SERIAL_SPEED 1
 
 /* key matrix size */
diff --git a/keyboards/handwired/tractyl_manuform/4x6_right/keymaps/drashna/config.h b/keyboards/handwired/tractyl_manuform/4x6_right/keymaps/drashna/config.h
index 21bc8e616a..d7bc0f5bd5 100644
--- a/keyboards/handwired/tractyl_manuform/4x6_right/keymaps/drashna/config.h
+++ b/keyboards/handwired/tractyl_manuform/4x6_right/keymaps/drashna/config.h
@@ -18,7 +18,6 @@
 
 // #define USE_I2C
 // #define SELECT_SOFT_SERIAL_SPEED 1
-// #define SERIAL_USE_MULTI_TRANSACTION
 #define SPLIT_MODS_ENABLE
 #define EE_HANDS
 
diff --git a/keyboards/helix/rev2/config.h b/keyboards/helix/rev2/config.h
index 2183bf7227..dcf88cc09c 100644
--- a/keyboards/helix/rev2/config.h
+++ b/keyboards/helix/rev2/config.h
@@ -27,7 +27,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 /* Soft Serial defines */
 #define SOFT_SERIAL_PIN D2
-#define SERIAL_USE_MULTI_TRANSACTION
 
 /* Select hand configuration */
 #define MASTER_LEFT
diff --git a/keyboards/helix/rev2/serial_config_simpleapi.h b/keyboards/helix/rev2/serial_config_simpleapi.h
index 0e1dd9e4ac..b51e6f281b 100644
--- a/keyboards/helix/rev2/serial_config_simpleapi.h
+++ b/keyboards/helix/rev2/serial_config_simpleapi.h
@@ -1,5 +1,4 @@
 #pragma once
 
-#undef SERIAL_USE_MULTI_TRANSACTION
 #define SERIAL_SLAVE_BUFFER_LENGTH MATRIX_ROWS/2
 #define SERIAL_MASTER_BUFFER_LENGTH MATRIX_ROWS/2
diff --git a/keyboards/lily58/config.h b/keyboards/lily58/config.h
index 57fc7fa7f9..740a3a5b1c 100644
--- a/keyboards/lily58/config.h
+++ b/keyboards/lily58/config.h
@@ -22,7 +22,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #ifndef SOFT_SERIAL_PIN
 #define SOFT_SERIAL_PIN D2
-#define SERIAL_USE_MULTI_TRANSACTION
 #endif
 
 #define DIODE_DIRECTION COL2ROW
diff --git a/keyboards/lily58/rev1/config.h b/keyboards/lily58/rev1/config.h
index 8205899f5e..b0ef4d165b 100644
--- a/keyboards/lily58/rev1/config.h
+++ b/keyboards/lily58/rev1/config.h
@@ -29,7 +29,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { F6, F7, B1, B3, B2, B6 }
 
 #define SOFT_SERIAL_PIN D2
-#define SERIAL_USE_MULTI_TRANSACTION
 
 /* define if matrix has ghost */
 //#define MATRIX_HAS_GHOST
diff --git a/keyboards/sofle/rev1/config.h b/keyboards/sofle/rev1/config.h
index f66588b43c..1556dc716e 100644
--- a/keyboards/sofle/rev1/config.h
+++ b/keyboards/sofle/rev1/config.h
@@ -23,5 +23,4 @@
 #define TAP_CODE_DELAY 10
 
 /* communication between sides */
-#define SERIAL_USE_MULTI_TRANSACTION
 #define SOFT_SERIAL_PIN D2
diff --git a/keyboards/uzu42/config.h b/keyboards/uzu42/config.h
index 3364d3063d..72bdafd38d 100644
--- a/keyboards/uzu42/config.h
+++ b/keyboards/uzu42/config.h
@@ -22,5 +22,4 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #ifndef SOFT_SERIAL_PIN
 #define SOFT_SERIAL_PIN D2
-#define SERIAL_USE_MULTI_TRANSACTION
 #endif