diff --git a/targets/CMSIS-OS/ChibiOS/nf-overlay/os/hal/src/stm32_onewire/hal_stm32_onewire.c b/targets/CMSIS-OS/ChibiOS/nf-overlay/os/hal/src/stm32_onewire/hal_stm32_onewire.c
index a01dd88cdf..6df9df438b 100644
--- a/targets/CMSIS-OS/ChibiOS/nf-overlay/os/hal/src/stm32_onewire/hal_stm32_onewire.c
+++ b/targets/CMSIS-OS/ChibiOS/nf-overlay/os/hal/src/stm32_onewire/hal_stm32_onewire.c
@@ -1012,7 +1012,7 @@ bool oneWireFindNext (bool doReset, bool alarmOnly)
     }
     while (romByteIndex < 8);  // loop until we have all ROM bytes
 
-    if (romBitIndex < (65 || lastcrc8))
+    if ((romBitIndex < 65) || (lastcrc8 != 0))
     {
         // search was unsuccessful reset the last discrepancy
         LastDiscrepancy = 0;
diff --git a/targets/FreeRTOS_ESP32/ESP32_WROOM_32/nanoCLR/nanoFramework.Devices.OneWire/nf_devices_onewire_native_nanoFramework_Devices_OneWire_OneWireController.cpp b/targets/FreeRTOS_ESP32/ESP32_WROOM_32/nanoCLR/nanoFramework.Devices.OneWire/nf_devices_onewire_native_nanoFramework_Devices_OneWire_OneWireController.cpp
index 4918457bf4..eb8929e09f 100644
--- a/targets/FreeRTOS_ESP32/ESP32_WROOM_32/nanoCLR/nanoFramework.Devices.OneWire/nf_devices_onewire_native_nanoFramework_Devices_OneWire_OneWireController.cpp
+++ b/targets/FreeRTOS_ESP32/ESP32_WROOM_32/nanoCLR/nanoFramework.Devices.OneWire/nf_devices_onewire_native_nanoFramework_Devices_OneWire_OneWireController.cpp
@@ -366,7 +366,7 @@ bool oneWireFindNext (bool doReset, bool alarmOnly)
     }
     while (romByteIndex < 8);  // loop until we have all ROM bytes
 
-    if (romBitIndex < (65 || lastcrc8))
+    if ((romBitIndex < 65) || (lastcrc8 != 0))
     {
         // search was unsuccessful reset the last discrepancy
         LastDiscrepancy = 0;