diff --git a/os/hal/platforms/STM32F2xx/hal_lld.h b/os/hal/platforms/STM32F2xx/hal_lld.h
index ae60b7806..ef0fc0283 100644
--- a/os/hal/platforms/STM32F2xx/hal_lld.h
+++ b/os/hal/platforms/STM32F2xx/hal_lld.h
@@ -399,10 +399,10 @@
 
 #define STM32_HAS_USART3        TRUE
 #define STM32_USART3_RX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 1))
-#define STM32_USART3_RX_DMA_CHN 0x00400400
+#define STM32_USART3_RX_DMA_CHN 0x00000040
 #define STM32_USART3_TX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 3) |            \
                                  STM32_DMA_STREAM_ID_MSK(1, 4))
-#define STM32_USART3_TX_DMA_CHN 0x00074040
+#define STM32_USART3_TX_DMA_CHN 0x00074000
 
 #define STM32_HAS_UART4         TRUE
 #define STM32_UART4_RX_DMA_MSK  (STM32_DMA_STREAM_ID_MSK(1, 2))
diff --git a/os/hal/platforms/STM32F4xx/hal_lld.h b/os/hal/platforms/STM32F4xx/hal_lld.h
index c88ac3a96..c4662cd14 100644
--- a/os/hal/platforms/STM32F4xx/hal_lld.h
+++ b/os/hal/platforms/STM32F4xx/hal_lld.h
@@ -398,10 +398,10 @@
 
 #define STM32_HAS_USART3        TRUE
 #define STM32_USART3_RX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 1))
-#define STM32_USART3_RX_DMA_CHN 0x00400400
+#define STM32_USART3_RX_DMA_CHN 0x00000040
 #define STM32_USART3_TX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 3) |            \
                                  STM32_DMA_STREAM_ID_MSK(1, 4))
-#define STM32_USART3_TX_DMA_CHN 0x00074040
+#define STM32_USART3_TX_DMA_CHN 0x00074000
 
 #define STM32_HAS_UART4         TRUE
 #define STM32_UART4_RX_DMA_MSK  (STM32_DMA_STREAM_ID_MSK(1, 2))
diff --git a/readme.txt b/readme.txt
index 4258925ad..5521d3349 100644
--- a/readme.txt
+++ b/readme.txt
@@ -79,6 +79,8 @@
 *****************************************************************************
 
 *** 2.5.0 ***
+- FIX: Fixed USART3 not working on STM32F2/F4 UART driver (bug 3496981)
+  (backported to 2.4.1).
 - FIX: Fixed stack misalignment on Posix-MacOSX (bug 3495487)(backported
   to 2.4.1).
 - FIX: Fixed STM8S HSI clock initialization error (bug 3489727)(backported to