diff --git a/doc/openocd.texi b/doc/openocd.texi
index cd64c7aec..01bb4f21d 100644
--- a/doc/openocd.texi
+++ b/doc/openocd.texi
@@ -3207,6 +3207,8 @@ able to coexist nicely with both sysfs bitbanging and various
 peripherals' kernel drivers. The driver restores the previous
 configuration on exit.
 
+GPIO numbers >= 32 can't be used for performance reasons.
+
 See @file{interface/raspberrypi-native.cfg} for a sample config and
 pinout.
 
diff --git a/src/jtag/drivers/bcm2835gpio.c b/src/jtag/drivers/bcm2835gpio.c
index 95e077c33..fd6c28b96 100644
--- a/src/jtag/drivers/bcm2835gpio.c
+++ b/src/jtag/drivers/bcm2835gpio.c
@@ -198,7 +198,7 @@ static int bcm2835gpio_speed(int speed)
 
 static int is_gpio_valid(int gpio)
 {
-	return gpio >= 0 && gpio <= 53;
+	return gpio >= 0 && gpio <= 31;
 }
 
 COMMAND_HANDLER(bcm2835gpio_handle_jtag_gpionums)