diff --git a/os/hal/ports/STM32/STM32F1xx/stm32_registry.h b/os/hal/ports/STM32/STM32F1xx/stm32_registry.h
index 0be4a37c0..e06ed276c 100644
--- a/os/hal/ports/STM32/STM32F1xx/stm32_registry.h
+++ b/os/hal/ports/STM32/STM32F1xx/stm32_registry.h
@@ -437,7 +437,14 @@
 #define STM32_HAS_LPUART1                   FALSE
 
 /* USB attributes.*/
+#if defined(STM32F103x6)
+#define STM32_HAS_USB                       TRUE
+#define STM32_USB_ACCESS_SCHEME_2x16        FALSE
+#define STM32_USB_PMA_SIZE                  512
+#define STM32_USB_HAS_BCDR                  FALSE
+#else
 #define STM32_HAS_USB                       FALSE
+#endif
 #define STM32_HAS_OTG1                      FALSE
 #define STM32_HAS_OTG2                      FALSE
 
@@ -637,10 +644,14 @@
 #define STM32_HAS_LPUART1                   FALSE
 
 /* USB attributes.*/
+#if defined(STM32F103xB)
 #define STM32_HAS_USB                       TRUE
 #define STM32_USB_ACCESS_SCHEME_2x16        FALSE
 #define STM32_USB_PMA_SIZE                  512
 #define STM32_USB_HAS_BCDR                  FALSE
+#else
+#define STM32_HAS_USB                       FALSE
+#endif
 #define STM32_HAS_OTG1                      FALSE
 #define STM32_HAS_OTG2                      FALSE
 
diff --git a/readme.txt b/readme.txt
index f10369fe3..7b7f239cc 100644
--- a/readme.txt
+++ b/readme.txt
@@ -102,6 +102,8 @@
        ARMv7-M and ARMv8-M-ML.
 - NEW: On STM32WBxx added a check on STM32_LSI_ENABLE required by IWDG.
 - NEW: Added SPIv2 support also to STM32WB and STM32WL.
+- FIX: Fixed USB not enabled on STM32F103x6 (bug #1206)
+       (backported to 20.3.5)(backported to 21.11.1).
 - FIX: Fixed RT test suite build fails when CH_CFG_USE_TIMESTAMP is FALSE
        (bug #1205)(backported to 21.11.1).
 - FIX: Fixed wrong number of CAN filters for STM32L496/9A6 (bug #1204)