diff --git a/devices/common_patches/l4_lcd_segment.yaml b/devices/common_patches/l4_lcd_segment.yaml
new file mode 100644
index 000000000..c51a5e0ab
--- /dev/null
+++ b/devices/common_patches/l4_lcd_segment.yaml
@@ -0,0 +1,15 @@
+# LCD RAM_COM registers are 64 bit wide, not 32.
+LCD:
+  _modify:
+    RAM_COM?:
+      size: 0x40
+  RAM_COM?:
+    _delete:
+      - "S??"
+    _add:
+      SEGS:
+        description: "Segment states, one bit per segment, LSB: S00, MSB: S39"
+        bitOffset: 0
+        bitWidth: 40
+  _array:
+    "RAM_COM?": {}
diff --git a/devices/stm32l4x3.yaml b/devices/stm32l4x3.yaml
index bdf0edc0a..843b96bc9 100644
--- a/devices/stm32l4x3.yaml
+++ b/devices/stm32l4x3.yaml
@@ -157,3 +157,4 @@ _include:
  - ./common_patches/l4_adc_sqr1.yaml
  - ./common_patches/l4_spi.yaml
  - ../peripherals/spi/spi_l4.yaml
+ - ./common_patches/l4_lcd_segment.yaml
diff --git a/devices/stm32l4x6.yaml b/devices/stm32l4x6.yaml
index fc88f5ea3..7ff3b90ff 100644
--- a/devices/stm32l4x6.yaml
+++ b/devices/stm32l4x6.yaml
@@ -76,3 +76,4 @@ _include:
  - ../peripherals/dma/dma2d_v1.yaml
  - ./common_patches/l4_spi.yaml
  - ../peripherals/spi/spi_l4.yaml
+ - ./common_patches/l4_lcd_segment.yaml