diff --git a/examples/device/cdc_dual_ports/src/main.c b/examples/device/cdc_dual_ports/src/main.c
index d4d07dcd6..0264f0566 100644
--- a/examples/device/cdc_dual_ports/src/main.c
+++ b/examples/device/cdc_dual_ports/src/main.c
@@ -55,17 +55,19 @@ int main(void)
 // with Serial0 as all lower case, Serial1 as all upper case
 static void echo_serial_port(uint8_t itf, uint8_t buf[], uint32_t count)
 {
+  uint8_t const case_diff = 'a' - 'A';
+
   for(uint32_t i=0; i<count; i++)
   {
     if (itf == 0)
     {
       // echo back 1st port as lower case
-      if (isupper(buf[i])) buf[i] = (uint8_t) (buf[i] + 'a' - 'A');
+      if (isupper(buf[i])) buf[i] += case_diff;
     }
     else
     {
       // echo back 2nd port as upper case
-      if (islower(buf[i])) buf[i] = (uint8_t) (buf[i] - 'a' - 'A');
+      if (islower(buf[i])) buf[i] -= case_diff;
     }
 
     tud_cdc_n_write_char(itf, buf[i]);
diff --git a/examples/device/hid_composite/src/main.c b/examples/device/hid_composite/src/main.c
index 3a3839a1a..05315f266 100644
--- a/examples/device/hid_composite/src/main.c
+++ b/examples/device/hid_composite/src/main.c
@@ -230,7 +230,7 @@ void tud_hid_report_complete_cb(uint8_t instance, uint8_t const* report, uint16_
   (void) instance;
   (void) len;
 
-  uint8_t next_report_id = (uint8_t)(report[0] + 1);
+  uint8_t next_report_id = report[0] + 1u;
 
   if (next_report_id < REPORT_ID_COUNT)
   {
diff --git a/examples/example.cmake b/examples/example.cmake
index 6bb82a56d..3e395d53f 100644
--- a/examples/example.cmake
+++ b/examples/example.cmake
@@ -21,5 +21,11 @@ target_compile_options(${PROJECT} PUBLIC
         -Wuninitialized
         -Wunused
         -Wredundant-decls
+        )
+
+# GCC version 9 or prior has a bug with incorrect Wconversion warnings
+if (CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 10.0)
+  target_compile_options(${PROJECT} PUBLIC
         -Wconversion
         )
+endif()
diff --git a/hw/bsp/rp2040/family.cmake b/hw/bsp/rp2040/family.cmake
index 794d02325..530d80fec 100644
--- a/hw/bsp/rp2040/family.cmake
+++ b/hw/bsp/rp2040/family.cmake
@@ -235,34 +235,31 @@ if (NOT TARGET _rp2040_family_inclusion_marker)
 
 	# This method must be called from the project scope to suppress known warnings in TinyUSB source files
 	function(suppress_tinyusb_warnings)
-		# some of these are pretty silly warnings only occurring in some older GCC versions
-		set(CONVERSION_WARNING_FILES
-				${PICO_TINYUSB_PATH}/src/tusb.c
-				${PICO_TINYUSB_PATH}/src/common/tusb_fifo.c
-				${PICO_TINYUSB_PATH}/src/device/usbd.c
-				${PICO_TINYUSB_PATH}/src/device/usbd_control.c
-				${PICO_TINYUSB_PATH}/src/host/usbh.c
-				${PICO_TINYUSB_PATH}/src/class/cdc/cdc_device.c
-				${PICO_TINYUSB_PATH}/src/class/cdc/cdc_host.c
-				${PICO_TINYUSB_PATH}/src/class/hid/hid_device.c
-				${PICO_TINYUSB_PATH}/src/class/hid/hid_host.c
-				${PICO_TINYUSB_PATH}/src/class/audio/audio_device.c
-				${PICO_TINYUSB_PATH}/src/class/dfu/dfu_device.c
-				${PICO_TINYUSB_PATH}/src/class/dfu/dfu_rt_device.c
-				${PICO_TINYUSB_PATH}/src/class/midi/midi_device.c
-				${PICO_TINYUSB_PATH}/src/class/usbtmc/usbtmc_device.c
-				${PICO_TINYUSB_PATH}/src/portable/raspberrypi/rp2040/hcd_rp2040.c
-				)
-		foreach(SOURCE_FILE IN LISTS CONVERSION_WARNING_FILES)
-			set_source_files_properties(
-					${SOURCE_FILE}
-					PROPERTIES
-					COMPILE_FLAGS "-Wno-conversion")
-		endforeach()
-		set_source_files_properties(
-				${PICO_TINYUSB_PATH}/src/portable/raspberrypi/rp2040/rp2040_usb.c
-				PROPERTIES
-				COMPILE_FLAGS "-Wno-stringop-overflow -Wno-array-bounds"
-		)
+		# some of these are pretty silly warnings only occurring in some older GCC versions 9 or prior
+		if (CMAKE_C_COMPILER_VERSION VERSION_LESS 10.0)
+  		set(CONVERSION_WARNING_FILES
+  				${PICO_TINYUSB_PATH}/src/tusb.c
+  				${PICO_TINYUSB_PATH}/src/common/tusb_fifo.c
+  				${PICO_TINYUSB_PATH}/src/device/usbd.c
+  				${PICO_TINYUSB_PATH}/src/device/usbd_control.c
+  				${PICO_TINYUSB_PATH}/src/host/usbh.c
+  				${PICO_TINYUSB_PATH}/src/class/cdc/cdc_device.c
+  				${PICO_TINYUSB_PATH}/src/class/cdc/cdc_host.c
+  				${PICO_TINYUSB_PATH}/src/class/hid/hid_device.c
+  				${PICO_TINYUSB_PATH}/src/class/hid/hid_host.c
+  				${PICO_TINYUSB_PATH}/src/class/audio/audio_device.c
+  				${PICO_TINYUSB_PATH}/src/class/dfu/dfu_device.c
+  				${PICO_TINYUSB_PATH}/src/class/dfu/dfu_rt_device.c
+  				${PICO_TINYUSB_PATH}/src/class/midi/midi_device.c
+  				${PICO_TINYUSB_PATH}/src/class/usbtmc/usbtmc_device.c
+  				${PICO_TINYUSB_PATH}/src/portable/raspberrypi/rp2040/hcd_rp2040.c
+  				)
+  		foreach(SOURCE_FILE IN LISTS CONVERSION_WARNING_FILES)
+  			set_source_files_properties(
+  					${SOURCE_FILE}
+  					PROPERTIES
+  					COMPILE_FLAGS "-Wno-conversion")
+  		endforeach()
+  	endif()
 	endfunction()
 endif()