diff --git a/FirmwareMain.cpp b/FirmwareMain.cpp
index 48accb7..2da033f 100644
--- a/FirmwareMain.cpp
+++ b/FirmwareMain.cpp
@@ -173,7 +173,7 @@ int main(void)
 
     delay(1);
 
-#if !defined(NO_SAM3XE_OVERCLOCK)
+#if defined(SAM3XE_OVERCLOCK)
     #define SYS_BOARD_PLLAR (CKGR_PLLAR_ONE | CKGR_PLLAR_MULA(18UL) | CKGR_PLLAR_PLLACOUNT(0x3fUL) | CKGR_PLLAR_DIVA(1UL))
     #define SYS_BOARD_MCKR ( PMC_MCKR_PRES_CLK_2 | PMC_MCKR_CSS_PLLA_CLK)