diff --git a/os/hal/include/dac.h b/os/hal/include/dac.h
index 65b0aa4eb..028d4fa78 100644
--- a/os/hal/include/dac.h
+++ b/os/hal/include/dac.h
@@ -243,14 +243,14 @@ extern "C" {
                       dacchannel_t channel,
                       dacsample_t sample);
   void dacStartConversion(DACDriver *dacp, const DACConversionGroup *grpp,
-                          const dacsample_t *samples, size_t depth);
+                          dacsample_t *samples, size_t depth);
   void dacStartConversionI(DACDriver *dacp, const DACConversionGroup *grpp,
-                           const dacsample_t *samples, size_t depth);
+                           dacsample_t *samples, size_t depth);
   void dacStopConversion(DACDriver *dacp);
   void dacStopConversionI(DACDriver *dacp);
 #if DAC_USE_WAIT
   msg_t dacConvert(DACDriver *dacp, const DACConversionGroup *grpp,
-                   const dacsample_t *samples, size_t depth);
+                   dacsample_t *samples, size_t depth);
 #endif
 #if DAC_USE_MUTUAL_EXCLUSION
   void dacAcquireBus(DACDriver *dacp);
diff --git a/os/hal/ports/STM32/LLD/DACv1/dac_lld.h b/os/hal/ports/STM32/LLD/DACv1/dac_lld.h
index 2589acb24..4ae673a3b 100644
--- a/os/hal/ports/STM32/LLD/DACv1/dac_lld.h
+++ b/os/hal/ports/STM32/LLD/DACv1/dac_lld.h
@@ -305,9 +305,7 @@ typedef enum {
  * @param[in] n         number of buffer rows available starting from @p buffer
  *                      callback
  */
-typedef void (*daccallback_t)(DACDriver *dacp,
-                              const dacsample_t *buffer,
-                              size_t n);
+typedef void (*daccallback_t)(DACDriver *dacp, dacsample_t *buffer, size_t n);
 
 /**
  * @brief   ADC error callback type.
@@ -392,7 +390,7 @@ struct DACDriver {
   /**
    * @brief   Samples buffer pointer.
    */
-  const dacsample_t         *samples;
+  dacsample_t               *samples;
   /**
    * @brief   Samples buffer size.
    */
diff --git a/os/hal/src/dac.c b/os/hal/src/dac.c
index c3c1b7c0c..1fba41656 100644
--- a/os/hal/src/dac.c
+++ b/os/hal/src/dac.c
@@ -165,7 +165,7 @@ void dacPutChannelX(DACDriver *dacp, dacchannel_t channel, dacsample_t sample) {
  */
 void dacStartConversion(DACDriver *dacp,
                         const DACConversionGroup *grpp,
-                        const dacsample_t *samples,
+                        dacsample_t *samples,
                         size_t depth) {
 
   osalSysLock();
@@ -193,7 +193,7 @@ void dacStartConversion(DACDriver *dacp,
  */
 void dacStartConversionI(DACDriver *dacp,
                          const DACConversionGroup *grpp,
-                         const dacsample_t *samples,
+                         dacsample_t *samples,
                          size_t depth) {
 
   osalDbgCheckClassI();
@@ -294,7 +294,7 @@ void dacStopConversionI(DACDriver *dacp) {
  */
 msg_t dacConvert(DACDriver *dacp,
                  const DACConversionGroup *grpp,
-                 const dacsample_t *samples,
+                 dacsample_t *samples,
                  size_t depth) {
   msg_t msg;
 
diff --git a/os/hal/templates/dac_lld.h b/os/hal/templates/dac_lld.h
index 5d437fffd..f8e4854cc 100644
--- a/os/hal/templates/dac_lld.h
+++ b/os/hal/templates/dac_lld.h
@@ -95,9 +95,7 @@ typedef enum {
  * @param[in] n         number of buffer rows available starting from @p buffer
  *                      callback
  */
-typedef void (*daccallback_t)(DACDriver *dacp,
-                              const dacsample_t *buffer,
-                              size_t n);
+typedef void (*daccallback_t)(DACDriver *dacp, dacsample_t *buffer, size_t n);
 
 /**
  * @brief   ADC error callback type.
@@ -150,7 +148,7 @@ struct DACDriver {
   /**
    * @brief   Samples buffer pointer.
    */
-  const dacsample_t         *samples;
+  dacsample_t               *samples;
   /**
    * @brief   Samples buffer size.
    */
diff --git a/readme.txt b/readme.txt
index ef70507b7..d22a12279 100644
--- a/readme.txt
+++ b/readme.txt
@@ -73,6 +73,7 @@
 *****************************************************************************
 
 *** 16.1.8 ***
+- HAL: Fixed DAC driver problem with API signature (bug #817).
 - HAL: Fixed STM32 OTGv1 driver not serving interrupts for endpoints > 5
        (bug #816).
 - HAL: Fixed STM32 MAC driver needs __DSB() for STM32F7 when operating in
diff --git a/testhal/STM32/STM32F3xx/DAC/main.c b/testhal/STM32/STM32F3xx/DAC/main.c
index c9a78cd33..75a70c696 100644
--- a/testhal/STM32/STM32F3xx/DAC/main.c
+++ b/testhal/STM32/STM32F3xx/DAC/main.c
@@ -59,7 +59,7 @@ static const dacsample_t dac_buffer[DAC_BUFFER_SIZE] = {
  * DAC streaming callback.
  */
 size_t nx = 0, ny = 0, nz = 0;
-static void end_cb1(DACDriver *dacp, const dacsample_t *buffer, size_t n) {
+static void end_cb1(DACDriver *dacp, dacsample_t *buffer, size_t n) {
 
   (void)dacp;
 
@@ -140,7 +140,8 @@ int main(void) {
   /*
    * Starting a continuous conversion.
    */
-  dacStartConversion(&DACD1, &dacgrpcfg1, dac_buffer, DAC_BUFFER_SIZE);
+  dacStartConversion(&DACD1, &dacgrpcfg1,
+                     (dacsample_t *)dac_buffer, DAC_BUFFER_SIZE);
   gptStartContinuous(&GPTD6, 2U);
 
   /*
diff --git a/testhal/STM32/STM32F4xx/DAC/main.c b/testhal/STM32/STM32F4xx/DAC/main.c
index 8f7b41253..cb3d08bb9 100644
--- a/testhal/STM32/STM32F4xx/DAC/main.c
+++ b/testhal/STM32/STM32F4xx/DAC/main.c
@@ -59,7 +59,7 @@ static const dacsample_t dac_buffer[DAC_BUFFER_SIZE] = {
  * DAC streaming callback.
  */
 size_t nx = 0, ny = 0, nz = 0;
-static void end_cb1(DACDriver *dacp, const dacsample_t *buffer, size_t n) {
+static void end_cb1(DACDriver *dacp, dacsample_t *buffer, size_t n) {
 
   (void)dacp;
 
@@ -140,7 +140,8 @@ int main(void) {
   /*
    * Starting a continuous conversion.
    */
-  dacStartConversion(&DACD1, &dacgrpcfg1, dac_buffer, DAC_BUFFER_SIZE);
+  dacStartConversion(&DACD1, &dacgrpcfg1,
+                     (dacsample_t *)dac_buffer, DAC_BUFFER_SIZE);
   gptStartContinuous(&GPTD6, 2U);
 
   /*
diff --git a/testhal/STM32/STM32F4xx/DAC_DUAL/main.c b/testhal/STM32/STM32F4xx/DAC_DUAL/main.c
index 0c96583eb..5b6a18bc9 100644
--- a/testhal/STM32/STM32F4xx/DAC_DUAL/main.c
+++ b/testhal/STM32/STM32F4xx/DAC_DUAL/main.c
@@ -59,7 +59,7 @@ static const dacsample_t dac_buffer[DAC_BUFFER_SIZE] = {
  * DAC streaming callback.
  */
 size_t nx = 0, ny = 0, nz = 0;
-static void end_cb1(DACDriver *dacp, const dacsample_t *buffer, size_t n) {
+static void end_cb1(DACDriver *dacp, dacsample_t *buffer, size_t n) {
 
   (void)dacp;
 
@@ -143,7 +143,8 @@ int main(void) {
    * Note, the buffer size is divided by two because two elements are fetched
    * for each transfer.
    */
-  dacStartConversion(&DACD1, &dacgrpcfg1, dac_buffer, DAC_BUFFER_SIZE / 2U);
+  dacStartConversion(&DACD1, &dacgrpcfg1,
+                     (dacsample_t *)dac_buffer, DAC_BUFFER_SIZE / 2U);
   gptStartContinuous(&GPTD6, 2U);
 
   /*
diff --git a/testhal/STM32/STM32L1xx/DAC/main.c b/testhal/STM32/STM32L1xx/DAC/main.c
index f7eb9bff3..b79521574 100644
--- a/testhal/STM32/STM32L1xx/DAC/main.c
+++ b/testhal/STM32/STM32L1xx/DAC/main.c
@@ -59,7 +59,7 @@ static const dacsample_t dac_buffer[DAC_BUFFER_SIZE] = {
  * DAC streaming callback.
  */
 size_t nx = 0, ny = 0, nz = 0;
-static void end_cb1(DACDriver *dacp, const dacsample_t *buffer, size_t n) {
+static void end_cb1(DACDriver *dacp, dacsample_t *buffer, size_t n) {
 
   (void)dacp;
 
@@ -140,7 +140,8 @@ int main(void) {
   /*
    * Starting a continuous conversion.
    */
-  dacStartConversion(&DACD1, &dacgrpcfg1, dac_buffer, DAC_BUFFER_SIZE);
+  dacStartConversion(&DACD1, &dacgrpcfg1,
+                     (dacsample_t *)dac_buffer, DAC_BUFFER_SIZE);
   gptStartContinuous(&GPTD6, 2U);
 
   /*