diff --git a/Makefile b/Makefile
index d6054c7..9fde372 100644
--- a/Makefile
+++ b/Makefile
@@ -230,8 +230,13 @@ CFLAGS += \
 	-Wall \
 	-Werror \
 	-Wfatal-errors \
+	-Wextra
 
-CFLAGS += -Wno-error=unused-parameter
+# Suppress warning caused by SDK
+CFLAGS += -Wno-error=unused-parameter -Wno-error=expansion-to-defined
+
+# TinyUSB tusb_hal_nrf_power_event
+CFLAGS += -Wno-error=cast-function-type
 
 # Defined Symbol (MACROS)
 CFLAGS += -D__HEAP_SIZE=0
diff --git a/src/usb/uf2/compile_date.h b/src/usb/uf2/compile_date.h
index d16f4ad..7175c83 100644
--- a/src/usb/uf2/compile_date.h
+++ b/src/usb/uf2/compile_date.h
@@ -50,22 +50,22 @@ SOFTWARE.
 :                                                  12u  /*Dec*/ )
 
 #define __DAY_INT__ ( \
-   (__DATE__ [4u] == ' ' ? 0u : __DATE__ [4u] - '0') * 10u \
+   (__DATE__ [4u] == ' ' ? 0 : __DATE__ [4u] - '0') * 10u \
  + (__DATE__ [5u] - '0')                                   )
 
 // __TIME__ expands to an eight-character string constant
 // "23:59:01", or (if cannot determine time) "??:??:??" 
 #define __HOUR_INT__ ( \
-   (__TIME__ [0u] == '?' ? 0u : __TIME__ [0u] - '0') * 10u \
- + (__TIME__ [1u] == '?' ? 0u : __TIME__ [1u] - '0')       )
+   (__TIME__ [0u] == '?' ? 0 : __TIME__ [0u] - '0') * 10u \
+ + (__TIME__ [1u] == '?' ? 0 : __TIME__ [1u] - '0')       )
 
 #define __MINUTE_INT__ ( \
-   (__TIME__ [3u] == '?' ? 0u : __TIME__ [3u] - '0') * 10u \
- + (__TIME__ [4u] == '?' ? 0u : __TIME__ [4u] - '0')       )
+   (__TIME__ [3u] == '?' ? 0 : __TIME__ [3u] - '0') * 10u \
+ + (__TIME__ [4u] == '?' ? 0 : __TIME__ [4u] - '0')       )
 
 #define __SECONDS_INT__ ( \
-   (__TIME__ [6u] == '?' ? 0u : __TIME__ [6u] - '0') * 10u \
- + (__TIME__ [7u] == '?' ? 0u : __TIME__ [7u] - '0')       )
+   (__TIME__ [6u] == '?' ? 0 : __TIME__ [6u] - '0') * 10u \
+ + (__TIME__ [7u] == '?' ? 0 : __TIME__ [7u] - '0')       )
 
 
 #define __DOSDATE__ ( \
diff --git a/src/usb/uf2/ghostfat.c b/src/usb/uf2/ghostfat.c
index 498c61e..28f1e0a 100644
--- a/src/usb/uf2/ghostfat.c
+++ b/src/usb/uf2/ghostfat.c
@@ -214,11 +214,11 @@ void read_block(uint32_t block_no, uint8_t *data) {
             // WARNING -- code presumes only one NULL .content for .UF2 file
             //            and all non-NULL .content fit in one sector
             //            and requires it be the last element of the array
-            for (int i = 1; i < NUM_FILES * 2 + 4; ++i) {
+            for (uint32_t i = 1; i < NUM_FILES * 2 + 4; ++i) {
                 data[i] = 0xff;
             }
         }
-        for (int i = 0; i < 256; ++i) { // Generate the FAT chain for the firmware "file"
+        for (uint32_t i = 0; i < 256; ++i) { // Generate the FAT chain for the firmware "file"
             uint32_t v = sectionIdx * 256 + i;
             if (UF2_FIRST_SECTOR <= v && v <= UF2_LAST_SECTOR)
                 ((uint16_t *)(void *)data)[i] = v == UF2_LAST_SECTOR ? 0xffff : v + 1;
@@ -237,7 +237,7 @@ void read_block(uint32_t block_no, uint8_t *data) {
             remainingEntries--;
         }
 
-        for (int i = DIRENTRIES_PER_SECTOR * sectionIdx;
+        for (uint32_t i = DIRENTRIES_PER_SECTOR * sectionIdx;
              remainingEntries > 0 && i < NUM_FILES;
              i++, d++) {