diff --git a/dts/bindings/flash_controller/st,stm32-qspi-nor.yaml b/dts/bindings/flash_controller/st,stm32-qspi-nor.yaml
index 8d53b4d08f8..1680610356b 100644
--- a/dts/bindings/flash_controller/st,stm32-qspi-nor.yaml
+++ b/dts/bindings/flash_controller/st,stm32-qspi-nor.yaml
@@ -6,9 +6,10 @@ description: |
 
     Representation of a serial flash on a quadspi bus:
 
-        mx25r6435f: qspi-nor-flash@90000000 {
+        mx25r6435f: qspi-nor-flash@0 {
                 compatible = "st,stm32-qspi-nor";
-                reg = <0x90000000 DT_SIZE_M(8)>; /* 64 Mbits */
+                reg = <0>;
+                size = <DT_SIZE_M(64)>; /* 64 Mbits */
                 qspi-max-frequency = <80000000>;
                 reset-gpios = <&gpiod 3 GPIO_ACTIVE_LOW>;
                 reset-gpios-duration = <1>;
@@ -23,6 +24,9 @@ include: ["flash-controller.yaml", "jedec,jesd216.yaml"]
 on-bus: qspi
 
 properties:
+  size:
+    required: true
+    description: Flash Memory size in bits
   reg:
     required: true
     description: Flash Memory base address and size in bytes