diff --git a/configtool.default.ini b/configtool.default.ini
index 3c09233..b3b8066 100644
--- a/configtool.default.ini
+++ b/configtool.default.ini
@@ -23,7 +23,7 @@ cflags = -DF_CPU=%%F_CPU%% -mmcu=%%CPU%% -Wall -Wstrict-prototypes -std=gnu99
          -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
          -Winline -fno-move-loop-invariants -fno-tree-scev-cprop -Os
          -ffunction-sections -finline-functions-called-once -mcall-prologues
-         -Wa,-adhlns=%%ALNAME%% -save-temps=obj
+         -flto -Wa,-adhlns=%%ALNAME%% -save-temps=obj
 
 # Flags passed to avr-gcc to be passed on to the linker.
 ldflags = -Wl,--as-needed -Wl,--gc-sections