diff --git a/os/hal/src/adc.c b/os/hal/src/adc.c
index 0a51a728e..80c0019e1 100644
--- a/os/hal/src/adc.c
+++ b/os/hal/src/adc.c
@@ -278,7 +278,7 @@ msg_t adcConvert(ADCDriver *adcp,
   msg_t msg;
 
   chSysLock();
-  chDbgAssert(grpp->acg_endcb == NULL, "adcConvert(), #1", "has callback");
+  chDbgAssert(adcp->ad_thread == NULL, "adcConvert(), #1", "already waiting");
   adcStartConversionI(adcp, grpp, samples, depth);
   (adcp)->ad_thread = chThdSelf();
   chSchGoSleepS(THD_STATE_SUSPENDED);
diff --git a/readme.txt b/readme.txt
index 92c2a5f3d..1e4064cfd 100644
--- a/readme.txt
+++ b/readme.txt
@@ -69,6 +69,7 @@
 *****************************************************************************
 
 *** 2.2.3 ***
+- FIX: Fixed invalid assertion in adcConvert() (bug 3205410).
 - NEW: Improved preemption implementation for the Cortex-M0, now it uses
   the NMI vector in order to restore the original context. The change makes
   IRQ handling faster and also saves some RAM/ROM space. The GCC port code