diff --git a/lib/si5351/si5351.h b/lib/si5351/si5351.h
--- a/lib/si5351/si5351.h
+++ b/lib/si5351/si5351.h
@@ -35,7 +35,7 @@
 /* Define definitions */
 
 #define SI5351_BUS_BASE_ADDR				((0x60 & 0x7f) << 1)
-#define SI5351_XTAL_FREQ					25000000
+#define SI5351_XTAL_FREQ					26000000
 #define SI5351_PLL_FIXED					90000000000ULL
 #define SI5351_FREQ_MULT					100ULL
 #define SI5351_DEFAULT_CLK					1000000000ULL