diff --git a/os/hal/platforms/STM32/mac_lld.c b/os/hal/platforms/STM32/mac_lld.c
index aff58342e..2799aab85 100644
--- a/os/hal/platforms/STM32/mac_lld.c
+++ b/os/hal/platforms/STM32/mac_lld.c
@@ -41,7 +41,11 @@
 #define BUFFER_SIZE ((((STM32_MAC_BUFFERS_SIZE - 1) | 3) + 1) / 4)
 
 /* MII divider optimal value.*/
-#if (STM32_HCLK >= 60000000)
+#if (STM32_HCLK >= 150000000)
+#define MACMIIDR_CR ETH_MACMIIAR_CR_Div102
+#elif (STM32_HCLK >= 100000000)
+#define MACMIIDR_CR ETH_MACMIIAR_CR_Div62
+#elif (STM32_HCLK >= 60000000)
 #define MACMIIDR_CR     ETH_MACMIIAR_CR_Div42
 #elif (STM32_HCLK >= 35000000)
 #define MACMIIDR_CR     ETH_MACMIIAR_CR_Div26
diff --git a/os/hal/platforms/STM32F2xx/hal_lld.h b/os/hal/platforms/STM32F2xx/hal_lld.h
index e704b7fa2..4d63324ce 100644
--- a/os/hal/platforms/STM32F2xx/hal_lld.h
+++ b/os/hal/platforms/STM32F2xx/hal_lld.h
@@ -221,10 +221,10 @@
 
 #define STM32_MCO1PRE_MASK      (7 << 24)   /**< MCO1PRE mask.              */
 #define STM32_MCO1PRE_DIV1      (0 << 24)   /**< MCO1 divided by 1.         */
-#define STM32_MCO1PRE_DIV2      (1 << 24)   /**< MCO1 divided by 2.         */
-#define STM32_MCO1PRE_DIV3      (2 << 24)   /**< MCO1 divided by 3.         */
-#define STM32_MCO1PRE_DIV4      (3 << 24)   /**< MCO1 divided by 4.         */
-#define STM32_MCO1PRE_DIV5      (4 << 24)   /**< MCO1 divided by 5.         */
+#define STM32_MCO1PRE_DIV2      (4 << 24)   /**< MCO1 divided by 2.         */
+#define STM32_MCO1PRE_DIV3      (5 << 24)   /**< MCO1 divided by 3.         */
+#define STM32_MCO1PRE_DIV4      (6 << 24)   /**< MCO1 divided by 4.         */
+#define STM32_MCO1PRE_DIV5      (7 << 24)   /**< MCO1 divided by 5.         */
 
 #define STM32_MCO2PRE_MASK      (7 << 27)   /**< MCO2PRE mask.              */
 #define STM32_MCO2PRE_DIV1      (0 << 27)   /**< MCO2 divided by 1.         */
diff --git a/os/hal/platforms/STM32F4xx/hal_lld.h b/os/hal/platforms/STM32F4xx/hal_lld.h
index 6cde89012..8c5303350 100644
--- a/os/hal/platforms/STM32F4xx/hal_lld.h
+++ b/os/hal/platforms/STM32F4xx/hal_lld.h
@@ -216,10 +216,10 @@
 
 #define STM32_MCO1PRE_MASK      (7 << 24)   /**< MCO1PRE mask.              */
 #define STM32_MCO1PRE_DIV1      (0 << 24)   /**< MCO1 divided by 1.         */
-#define STM32_MCO1PRE_DIV2      (1 << 24)   /**< MCO1 divided by 2.         */
-#define STM32_MCO1PRE_DIV3      (2 << 24)   /**< MCO1 divided by 3.         */
-#define STM32_MCO1PRE_DIV4      (3 << 24)   /**< MCO1 divided by 4.         */
-#define STM32_MCO1PRE_DIV5      (4 << 24)   /**< MCO1 divided by 5.         */
+#define STM32_MCO1PRE_DIV2      (4 << 24)   /**< MCO1 divided by 2.         */
+#define STM32_MCO1PRE_DIV3      (5 << 24)   /**< MCO1 divided by 3.         */
+#define STM32_MCO1PRE_DIV4      (6 << 24)   /**< MCO1 divided by 4.         */
+#define STM32_MCO1PRE_DIV5      (7 << 24)   /**< MCO1 divided by 5.         */
 
 #define STM32_MCO2PRE_MASK      (7 << 27)   /**< MCO2PRE mask.              */
 #define STM32_MCO2PRE_DIV1      (0 << 27)   /**< MCO2 divided by 1.         */
diff --git a/readme.txt b/readme.txt
index 36b2dd1bb..42fbb8349 100644
--- a/readme.txt
+++ b/readme.txt
@@ -81,6 +81,10 @@
 *****************************************************************************
 
 *** 2.5.0 ***
+- FIX: Fixed wrong MAC divider setting in STM32 MAC driver (bug 3531290)
+  (backported to 2.4.2).
+- FIX: Fixed wrong MCO1 divider in STM32F2/F4 HAL (bug 3531289)(backported
+  to 2.4.2).
 - FIX: Fixed missing "break" in AVR PAL driver (bug 3530924)(backported
   to 2.4.2).
 - FIX: Fixed timeout related race condition in STM32 I2C driver (bug 3530043)