diff --git a/os/hal/ports/STM32/LLD/mac_lld.c b/os/hal/ports/STM32/LLD/mac_lld.c
index 73c699062..5142df163 100644
--- a/os/hal/ports/STM32/LLD/mac_lld.c
+++ b/os/hal/ports/STM32/LLD/mac_lld.c
@@ -123,22 +123,20 @@ static void mii_find_phy(MACDriver *macp) {
   uint32_t i;
 
 #if STM32_MAC_PHY_TIMEOUT > 0
-  rtcnt_t start = chSysGetRealtimeCounterX();
-  rtcnt_t timeout  = start + MS2RTC(STM32_HCLK,STM32_MAC_PHY_TIMEOUT);
-  rtcnt_t time = start;
-  while (chSysIsCounterWithinX(time, start, timeout)) {
+  unsigned n = STM32_MAC_PHY_TIMEOUT;
+ do {
 #endif
-    for (i = 0; i < 31; i++) {
-      macp->phyaddr = i << 11;
-      ETH->MACMIIDR = (i << 6) | MACMIIDR_CR;
-      if ((mii_read(macp, MII_PHYSID1) == (BOARD_PHY_ID >> 16)) &&
-          ((mii_read(macp, MII_PHYSID2) & 0xFFF0) == (BOARD_PHY_ID & 0xFFF0))) {
+    for (i = 0U; i < 31U; i++) {
+      macp->phyaddr = i << 11U;
+      ETH->MACMIIDR = (i << 6U) | MACMIIDR_CR;
+      if ((mii_read(macp, MII_PHYSID1) == (BOARD_PHY_ID >> 16U)) &&
+          ((mii_read(macp, MII_PHYSID2) & 0xFFF0U) == (BOARD_PHY_ID & 0xFFF0U))) {
         return;
       }
     }
 #if STM32_MAC_PHY_TIMEOUT > 0
-    time = chSysGetRealtimeCounterX();
-  }
+    n--;
+  } while (n > 0U);
 #endif
   /* Wrong or defective board.*/
   osalSysHalt("MAC failure");
diff --git a/os/hal/ports/STM32/LLD/mac_lld.h b/os/hal/ports/STM32/LLD/mac_lld.h
index 96987cf95..8684192a5 100644
--- a/os/hal/ports/STM32/LLD/mac_lld.h
+++ b/os/hal/ports/STM32/LLD/mac_lld.h
@@ -144,12 +144,11 @@
 
 /**
  * @brief   PHY detection timeout.
- * @details Timeout, in milliseconds, for PHY address detection, if a PHY
- *          is not detected within the timeout then the driver halts during
- *          initialization. This setting applies only if the PHY address is
- *          not explicitly set in the board header file using
- *          @p BOARD_PHY_ADDRESS. A zero value disables the timeout and a
- *          single search path is performed.
+ * @details Timeout for PHY address detection, the scan for a PHY is performed
+ *          the specified number of times before invoking the failure handler.
+ *          This setting applies only if the PHY address is not explicitly
+ *          set in the board header file using @p BOARD_PHY_ADDRESS. A zero
+ *          value disables the timeout and a single search is performed.
  */
 #if !defined(STM32_MAC_PHY_TIMEOUT) || defined(__DOXYGEN__)
 #define STM32_MAC_PHY_TIMEOUT               100
diff --git a/readme.txt b/readme.txt
index 5f25b8ef0..4cd7437cd 100644
--- a/readme.txt
+++ b/readme.txt
@@ -80,6 +80,7 @@
 - NIL: Added INTC priorities check to the e200z port.
 - RT:  Added INTC priorities check to the e200z port.
 - HAL: Added support for extra DMA channels in STM32F072 devices.
+- HAL: Fixed dependency between STM32 MAC driver and RT (bug #606).
 - HAL: Fixed wrong macro names in STM32F0xx HAL driver (bug #605).
 - HAL: Fixed wrong check on ADC3 in STM32F3xx ADC driver (bug #604).
 - HAL: Fixed wrong macro names in STM32F3xx HAL driver (bug #603).