diff --git a/keyboards/40percentclub/nano/config.h b/keyboards/40percentclub/nano/config.h
index 5eb65c74ad..8ee6963e49 100644
--- a/keyboards/40percentclub/nano/config.h
+++ b/keyboards/40percentclub/nano/config.h
@@ -50,9 +50,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
-//#define DIODE_DIRECTION CUSTOM_MATRIX
-
 /* ws2812 RGB LED */
 #define RGB_DI_PIN D3
 #define RGBLIGHT_ANIMATIONS
diff --git a/keyboards/abstract/ellipse/rev1/config.h b/keyboards/abstract/ellipse/rev1/config.h
index 36a4fc40f2..15606f3d44 100644
--- a/keyboards/abstract/ellipse/rev1/config.h
+++ b/keyboards/abstract/ellipse/rev1/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { F0, B6, B5 }
 #define UNUSED_PINS { B0, D0, D1, D2, D4, D6, D7, F1, F4, F5, F6, F7 }
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 #define BACKLIGHT_PIN C6
diff --git a/keyboards/ai03/orbit/config.h b/keyboards/ai03/orbit/config.h
index 00945ac796..051b924b87 100644
--- a/keyboards/ai03/orbit/config.h
+++ b/keyboards/ai03/orbit/config.h
@@ -54,7 +54,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /*
diff --git a/keyboards/boardwalk/config.h b/keyboards/boardwalk/config.h
index 7747502083..fa80673d80 100644
--- a/keyboards/boardwalk/config.h
+++ b/keyboards/boardwalk/config.h
@@ -43,7 +43,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { F7, C7, C6, B6, B5, B4, D7, D6, D4, D5, D3, D2, D1, D0 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 // #define BACKLIGHT_PIN F5
diff --git a/keyboards/ckeys/thedora/config.h b/keyboards/ckeys/thedora/config.h
index f2b93ee70e..a3d30c3043 100755
--- a/keyboards/ckeys/thedora/config.h
+++ b/keyboards/ckeys/thedora/config.h
@@ -39,7 +39,7 @@
 
 // #define UNUSED_PINS { B14 }
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 //#define BACKLIGHT_PIN B7
diff --git a/keyboards/converter/palm_usb/config.h b/keyboards/converter/palm_usb/config.h
index 4233a53ef0..8414c47a77 100644
--- a/keyboards/converter/palm_usb/config.h
+++ b/keyboards/converter/palm_usb/config.h
@@ -23,8 +23,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #pragma once
 
-#define CUSTOM_MATRIX 2
-
 #define VENDOR_ID       0xFEED
 #define PRODUCT_ID      0x0001
 #define DEVICE_VER      0x0100
diff --git a/keyboards/converter/sun_usb/config.h b/keyboards/converter/sun_usb/config.h
index 7713e0a915..455d6423b5 100644
--- a/keyboards/converter/sun_usb/config.h
+++ b/keyboards/converter/sun_usb/config.h
@@ -18,8 +18,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef CONFIG_H
 #define CONFIG_H
 
-#define CUSTOM_MATRIX 2
-
 #define VENDOR_ID       0xFEED
 #define PRODUCT_ID      0x3333
 #define DEVICE_VER      0x0100
diff --git a/keyboards/converter/usb_usb/config.h b/keyboards/converter/usb_usb/config.h
index fdaf42eda4..7af8950275 100644
--- a/keyboards/converter/usb_usb/config.h
+++ b/keyboards/converter/usb_usb/config.h
@@ -18,12 +18,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifndef CONFIG_H
 #define CONFIG_H
 
-// do not #include "config_common.h" because the pin names conflict with the USB HID code.
-// CUSTOM_MATRIX is defined it that file, though, and we need it, so we define it ourselves.
-// It's a hack, yeah...
-
-#define CUSTOM_MATRIX 2
-
 /* USB Device descriptor parameter */
 #define VENDOR_ID       0xFEED
 #define PRODUCT_ID      0x005B
@@ -36,9 +30,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_ROWS 16
 #define MATRIX_COLS 16
 
-/* matrix scanning is done in custom_matrix.cpp */
-//#define DIODE_DIRECTION
-
 /*
  * Feature disable options
  *  These options are also useful to firmware size reduction.
diff --git a/keyboards/coseyfannitutti/mullet/config.h b/keyboards/coseyfannitutti/mullet/config.h
index 2025cb4333..f9aef2911c 100644
--- a/keyboards/coseyfannitutti/mullet/config.h
+++ b/keyboards/coseyfannitutti/mullet/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { B2, F4, F5, F6, F7, C7, C6, B6, B5, B4, D7, D6, D4, D2, D3 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 // #define BACKLIGHT_PIN B7
diff --git a/keyboards/coseyfannitutti/mulletpad/config.h b/keyboards/coseyfannitutti/mulletpad/config.h
index 2174d64925..4e25ec0337 100644
--- a/keyboards/coseyfannitutti/mulletpad/config.h
+++ b/keyboards/coseyfannitutti/mulletpad/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { F0, C7, C6, B6, }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 // #define BACKLIGHT_PIN B7
diff --git a/keyboards/dozen0/config.h b/keyboards/dozen0/config.h
index af6972e27b..3fdd50f504 100644
--- a/keyboards/dozen0/config.h
+++ b/keyboards/dozen0/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { B6, B2, B3, B1, F7, F6, B5, B4, E6, D7, C6, D4 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 // #define BACKLIGHT_PIN B7
diff --git a/keyboards/ep/comsn/hs68/config.h b/keyboards/ep/comsn/hs68/config.h
index db633a2509..cf15a90bb4 100644
--- a/keyboards/ep/comsn/hs68/config.h
+++ b/keyboards/ep/comsn/hs68/config.h
@@ -47,7 +47,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
   { B0, B1, B3, B2, B7, D3, F1, D5, D6, D7, F4, F5, C7, C6, F0 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/ep/comsn/mollydooker/config.h b/keyboards/ep/comsn/mollydooker/config.h
index 3ba661525a..2a96b53414 100644
--- a/keyboards/ep/comsn/mollydooker/config.h
+++ b/keyboards/ep/comsn/mollydooker/config.h
@@ -47,7 +47,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
   { B1, B2, B3, E6, B7, F1, F0, D0, D1, D7, D5, D4, D6, B4, B5, D3, B6, C6, C7 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 // #endif
diff --git a/keyboards/fluorite/config.h b/keyboards/fluorite/config.h
index 59af3eb265..7bae8a013c 100644
--- a/keyboards/fluorite/config.h
+++ b/keyboards/fluorite/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { D3, D1, D0, D4, C6, D7, E6, B4, B5 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /*
diff --git a/keyboards/halberd/config.h b/keyboards/halberd/config.h
index cf3460b618..57e29e858e 100644
--- a/keyboards/halberd/config.h
+++ b/keyboards/halberd/config.h
@@ -44,7 +44,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { D7, B4, C7, C6, B6, B5, F7, F6, F5, F4, F1 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 // #define BACKLIGHT_PIN B7
diff --git a/keyboards/handwired/42/config.h b/keyboards/handwired/42/config.h
index 3f5060989b..c88013f460 100644
--- a/keyboards/handwired/42/config.h
+++ b/keyboards/handwired/42/config.h
@@ -28,7 +28,7 @@
 #define MATRIX_ROW_PINS { D2, D3, D0, D1 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/handwired/co60/rev1/config.h b/keyboards/handwired/co60/rev1/config.h
index 4d5140dafd..2168516d2d 100644
--- a/keyboards/handwired/co60/rev1/config.h
+++ b/keyboards/handwired/co60/rev1/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { F0, F1, E6, C7, C6, B6, D4, B1, B2, B5, B4, D7, D6, B3, B0 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 #ifdef __AVR__
diff --git a/keyboards/handwired/co60/rev6/config.h b/keyboards/handwired/co60/rev6/config.h
index a2c73853ca..0a7227fb8e 100644
--- a/keyboards/handwired/co60/rev6/config.h
+++ b/keyboards/handwired/co60/rev6/config.h
@@ -41,7 +41,7 @@
 #define MATRIX_ROW_PINS { B0, B1, B2, A15, A10 }
 #define MATRIX_COL_PINS { A2, A3, A6, B14, B15, A8, A9, A7, B3, B4, C14, C15, C13, B5, B6 }
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/handwired/co60/rev7/config.h b/keyboards/handwired/co60/rev7/config.h
index e13d28f507..98b36b99cc 100644
--- a/keyboards/handwired/co60/rev7/config.h
+++ b/keyboards/handwired/co60/rev7/config.h
@@ -43,7 +43,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { A10, A9, A3, A4, A5, A6, B0, B1, A15, B3, B4, B5, C13, C14, C15 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/handwired/daishi/config.h b/keyboards/handwired/daishi/config.h
index b4665bece4..16ca49ba17 100644
--- a/keyboards/handwired/daishi/config.h
+++ b/keyboards/handwired/daishi/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { E6, E7, E3, B0, B1, B2, A6, A5, A4, A3, A2, A1, A0, F7, F6, F5, F4, F3 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/handwired/steamvan/rev1/config.h b/keyboards/handwired/steamvan/rev1/config.h
index f47dc90c19..78e46b3437 100644
--- a/keyboards/handwired/steamvan/rev1/config.h
+++ b/keyboards/handwired/steamvan/rev1/config.h
@@ -43,7 +43,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { A9, A8, B15, B14, B13, A10, B9, B6, B5, B4, B3, A15 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/handwired/tennie/config.h b/keyboards/handwired/tennie/config.h
index 20795b048c..d26cb4c616 100644
--- a/keyboards/handwired/tennie/config.h
+++ b/keyboards/handwired/tennie/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { D7, E6, B4, B5 }
 #define UNUSED_PINS { B1, B2, B3, B6, F4, F5, F6, F7 D1}
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /*
diff --git a/keyboards/hecomi/alpha/config.h b/keyboards/hecomi/alpha/config.h
index dbc94454f9..3600eb717d 100644
--- a/keyboards/hecomi/alpha/config.h
+++ b/keyboards/hecomi/alpha/config.h
@@ -48,7 +48,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define SOFT_SERIAL_PIN D1 // or D1, D2, D3, E6
 //#define USE_I2C
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /*
diff --git a/keyboards/kagamidget/config.h b/keyboards/kagamidget/config.h
index 7fe67ffd33..c887302158 100644
--- a/keyboards/kagamidget/config.h
+++ b/keyboards/kagamidget/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { D4, C6, D7, E6, B4, B5, B6, B2, B3, B1, F7, F6 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 
diff --git a/keyboards/peiorisboards/ixora/config.h b/keyboards/peiorisboards/ixora/config.h
index bf74b13cc1..77ba89c292 100644
--- a/keyboards/peiorisboards/ixora/config.h
+++ b/keyboards/peiorisboards/ixora/config.h
@@ -17,7 +17,7 @@
 #define MATRIX_ROW_PINS { A0 }
 #define MATRIX_COL_PINS { B4, A15, B3, A1, B6, B5 }
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/primekb/prime_e/config.h b/keyboards/primekb/prime_e/config.h
index bf5061b1ae..c564752038 100644
--- a/keyboards/primekb/prime_e/config.h
+++ b/keyboards/primekb/prime_e/config.h
@@ -36,7 +36,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { F0, F1, F4, F5, F6, F7, D6, D4, D5, D3, D2, D1, D0 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 #define BACKLIGHT_PIN B7
diff --git a/keyboards/scythe/config.h b/keyboards/scythe/config.h
index d577192db3..c4d12bb030 100644
--- a/keyboards/scythe/config.h
+++ b/keyboards/scythe/config.h
@@ -46,7 +46,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #define SOFT_SERIAL_PIN D0
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 #define BACKLIGHT_PIN B7
diff --git a/keyboards/sirius/unigo66/config.h b/keyboards/sirius/unigo66/config.h
index 66f7f9542f..3eed36bc0c 100644
--- a/keyboards/sirius/unigo66/config.h
+++ b/keyboards/sirius/unigo66/config.h
@@ -17,8 +17,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #pragma once
 
-#define CUSTOM_MATRIX 2
-
 /* USB Device descriptor parameter */
 #define VENDOR_ID       0xFEED
 #define PRODUCT_ID      0x1001
@@ -31,9 +29,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_ROWS 16
 #define MATRIX_COLS 16
 
-/* matrix scanning is done in custom_matrix.cpp */
-//#define DIODE_DIRECTION
-
 /*
  * Feature disable options
  *  These options are also useful to firmware size reduction.
diff --git a/keyboards/snampad/config.h b/keyboards/snampad/config.h
index a2dc3c6dd5..86dd3ce2fc 100644
--- a/keyboards/snampad/config.h
+++ b/keyboards/snampad/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { D0, D1, D2, D3  }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION ROW2COL
 
 /*
diff --git a/keyboards/standaside/config.h b/keyboards/standaside/config.h
index 80c9f8d21b..92c6b28b97 100644
--- a/keyboards/standaside/config.h
+++ b/keyboards/standaside/config.h
@@ -31,7 +31,7 @@
 #define UNUSED_PINS {}
 
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 // #define BACKLIGHT_PIN C7
diff --git a/keyboards/treadstone32/config.h b/keyboards/treadstone32/config.h
index a7f9914536..b9cd94d4b6 100644
--- a/keyboards/treadstone32/config.h
+++ b/keyboards/treadstone32/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { F4, F5, F6, F7, C7 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 /* Debounce reduces chatter (unintended double-presses) - set 0 if debouncing is not needed */
diff --git a/keyboards/westfoxtrot/cypher/config.h b/keyboards/westfoxtrot/cypher/config.h
index 1378837037..33bdaa2042 100644
--- a/keyboards/westfoxtrot/cypher/config.h
+++ b/keyboards/westfoxtrot/cypher/config.h
@@ -45,7 +45,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MATRIX_COL_PINS { D0, D1, D2, D3, D4, D5, D6, D7, E6, F0 }
 #define UNUSED_PINS
 
-/* COL2ROW, ROW2COL, or CUSTOM_MATRIX */
+/* COL2ROW, ROW2COL */
 #define DIODE_DIRECTION COL2ROW
 
 #define BACKLIGHT_PIN B5
diff --git a/quantum/config_common.h b/quantum/config_common.h
index c1c1d4bd42..8de3f070c5 100644
--- a/quantum/config_common.h
+++ b/quantum/config_common.h
@@ -19,7 +19,6 @@
 /* diode directions */
 #define COL2ROW 0
 #define ROW2COL 1
-#define CUSTOM_MATRIX 2 /* Disables built-in matrix scanning code */
 
 // useful for direct pin mapping
 #define NO_PIN (~0)