diff --git a/firmware/avr-toolchain.cmake b/firmware/avr-toolchain.cmake
index 4b97bd1..2d3c685 100644
--- a/firmware/avr-toolchain.cmake
+++ b/firmware/avr-toolchain.cmake
@@ -63,7 +63,7 @@ function(add_avr_executable EXECUTABLE_NAME)
    set_target_properties(
       ${elf_file}
       PROPERTIES
-         COMPILE_FLAGS "-mmcu=${AVR_MCU}"
+         COMPILE_FLAGS "-mmcu=${AVR_MCU} -O3"
          LINK_FLAGS "-mmcu=${AVR_MCU} -Wl,--gc-sections -mrelax -Wl,-Map,${map_file}"
    )