diff --git a/tcl/target/stm32f4x.cfg b/tcl/target/stm32f4x.cfg
index ecd39de77..a7ec5eab3 100644
--- a/tcl/target/stm32f4x.cfg
+++ b/tcl/target/stm32f4x.cfg
@@ -73,13 +73,13 @@ $_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE
 set _FLASHNAME $_CHIPNAME.flash
 flash bank $_FLASHNAME stm32f2x 0 0 0 0 $_TARGETNAME
 
-# JTAG speed should be <= F_CPU/6. F_CPU after reset is 8MHz, so use F_JTAG = 1MHz
+# JTAG speed should be <= F_CPU/6. F_CPU after reset is 16MHz, so use F_JTAG = 2MHz
 #
 # Since we may be running of an RC oscilator, we crank down the speed a
 # bit more to be on the safe side. Perhaps superstition, but if are
 # running off a crystal, we can run closer to the limit. Note
 # that there can be a pretty wide band where things are more or less stable.
-adapter_khz 1000
+adapter_khz 2000
 
 adapter_nsrst_delay 100
 if {[using_jtag]} {