diff --git a/config/corne.keymap b/config/corne.keymap
index 5b9fe51b..cfb2e0b7 100644
--- a/config/corne.keymap
+++ b/config/corne.keymap
@@ -9,6 +9,19 @@
 #include <dt-bindings/zmk/keys.h>
 #include <dt-bindings/zmk/pointing.h>
 
+#define KEYS_L LT0 LT1 LT2 LT3 LT4 LM0 LM1 LM2 LM3 LM4 LB0 LB1 LB2 LB3 LB4
+#define KEYS_R RT0 RT1 RT2 RT3 RT4 RM0 RM1 RM2 RM3 RM4 RB0 RB1 RB2 RB3 RB4
+#define THUMBS LH2 LH1 LH0 RH0 RH1 RH2 // Thumbs on 36+ keys.
+
+#define MAKE_HRM(NAME, HOLD, TAP, TRIGGER_POS)                                 \
+  ZMK_HOLD_TAP(NAME, bindings = <HOLD>, <TAP>; flavor = "balanced";            \
+               tapping-term-ms = <280>; quick-tap-ms = <QUICK_TAP_MS>;         \
+               require-prior-idle-ms = <150>; hold-trigger-on-release;         \
+               hold-trigger-key-positions = <TRIGGER_POS>;)
+
+MAKE_HRM(hml, &kp, &kp, KEYS_R THUMBS) // Left-hand HRMs.
+MAKE_HRM(hmr, &kp, &kp, KEYS_L THUMBS) // Right-hand HRMs.
+
 &lt {
     flavor = "hold-preferred";
     tapping-term-ms = <200>;
@@ -23,7 +36,7 @@
     behaviors {
         space: space {
             compatible = "zmk,behavior-hold-tap";
-            label = "SPACE";
+            label = "Space";
             bindings = <&kp>, <&kp>;
 
             #binding-cells = <2>;
@@ -39,7 +52,7 @@
             label = "Base";
             bindings = <
 &kp TAB    &kp Q                &kp W                  &kp E              &kp R               &kp T          &kp Y            &kp U               &kp I                &kp O                   &kp P                         &kp BACKSLASH
-&kp TAB    &space LEFT_SHIFT A  &space LEFT_CONTROL S  &space LEFT_GUI D  &space LEFT_ALT F   &kp G          &kp H            &space RIGHT_ALT J  &space RIGHT_GUI K   &space RIGHT_CONTROL L  &space RIGHT_SHIFT SEMICOLON  &kp SQT
+&kp TAB    &hml LEFT_SHIFT A  &hml LEFT_CONTROL S  &hml LEFT_GUI D  &hml LEFT_ALT F   &kp G          &kp H            &hmr RIGHT_ALT J  &hmr RIGHT_GUI K   &hmr RIGHT_CONTROL L  &hmr RIGHT_SHIFT SEMICOLON  &kp SQT
 &kp GRAVE  &kp Z                &kp X                  &kp C              &kp V               &kp B          &kp N            &kp M               &kp COMMA            &kp DOT                 &kp FSLH                      &kp RIGHT_SHIFT
                                                        &mt LEFT_ALT TAB   &space LCTRL SPACE  &lt 2 ENTER    &lt 1 BACKSPACE  &mt RSHIFT ESC      &mt RIGHT_GUI SPACE
             >;