diff --git a/os/hal/include/hal_adc.h b/os/hal/include/hal_adc.h
index 7b93851c5..527821245 100644
--- a/os/hal/include/hal_adc.h
+++ b/os/hal/include/hal_adc.h
@@ -230,8 +230,12 @@ typedef enum {
     (adcp)->grpp->error_cb(adcp, err);                                      \
     if ((adcp)->state == ADC_ERROR)                                         \
       (adcp)->state = ADC_READY;                                            \
+      (adcp)->grpp = NULL;                                                  \
+  }                                                                         \
+  else {                                                                    \
+    (adcp)->state = ADC_READY;                                              \
+    (adcp)->grpp = NULL;                                                    \
   }                                                                         \
-  (adcp)->grpp = NULL;                                                      \
   _adc_timeout_isr(adcp);                                                   \
 }
 /** @} */
diff --git a/readme.txt b/readme.txt
index 276e1ca1b..f3df0aa41 100644
--- a/readme.txt
+++ b/readme.txt
@@ -114,6 +114,8 @@
 - RT:  Merged RT4.
 - NIL: Merged NIL2.
 - NIL: Added STM32F7 demo.
+- HAL: Fixed wrong conditional branches in _adc_isr_error_code (bug #751)
+       (backported to 2.6.10, 3.0.6 and 16.1.5).
 - HAL: Fixed bug in STM32/ADCv3 (bug #750).
 - HAL: Fixed OPT settings and added board folder in STM32F4xx-USB_CDC demo
        (bug #749)(backported to 3.0.6 and 16.1.5).