diff --git a/cpu/mpc83xx/fdt.c b/cpu/mpc83xx/fdt.c
index 267ae6a..fda85c1 100644
--- a/cpu/mpc83xx/fdt.c
+++ b/cpu/mpc83xx/fdt.c
@@ -78,7 +78,7 @@ void ft_cpu_setup(void *blob, bd_t *bd)
 
 #ifdef CFG_NS16550
 	do_fixup_by_compat_u32(blob, "ns16550",
-		"clock-frequency", bd->bi_busfreq, 1);
+		"clock-frequency", CFG_NS16550_CLK, 1);
 #endif
 
 	fdt_fixup_memory(blob, (u64)bd->bi_memstart, (u64)bd->bi_memsize);
diff --git a/cpu/mpc85xx/fdt.c b/cpu/mpc85xx/fdt.c
index c8d2c6a..c159934 100644
--- a/cpu/mpc85xx/fdt.c
+++ b/cpu/mpc85xx/fdt.c
@@ -229,7 +229,7 @@ void ft_cpu_setup(void *blob, bd_t *bd)
 
 #ifdef CFG_NS16550
 	do_fixup_by_compat_u32(blob, "ns16550",
-		"clock-frequency", bd->bi_busfreq, 1);
+		"clock-frequency", CFG_NS16550_CLK, 1);
 #endif
 
 #ifdef CONFIG_CPM2
diff --git a/cpu/mpc86xx/fdt.c b/cpu/mpc86xx/fdt.c
index 379306e..80a5c78 100644
--- a/cpu/mpc86xx/fdt.c
+++ b/cpu/mpc86xx/fdt.c
@@ -30,6 +30,6 @@ void ft_cpu_setup(void *blob, bd_t *bd)
 
 #ifdef CFG_NS16550
 	do_fixup_by_compat_u32(blob, "ns16550",
-			       "clock-frequency", bd->bi_busfreq, 1);
+			       "clock-frequency", CFG_NS16550_CLK, 1);
 #endif
 }