diff --git a/hardware/fx2lafw/command.c b/hardware/fx2lafw/command.c
index 07f6b4ad..91a286ce 100644
--- a/hardware/fx2lafw/command.c
+++ b/hardware/fx2lafw/command.c
@@ -22,8 +22,8 @@
 #include "sigrok.h"
 #include "sigrok-internal.h"
 
-int command_start_acquisition(libusb_device_handle *devhdl,
-			      uint64_t samplerate)
+SR_PRIV int command_start_acquisition(libusb_device_handle *devhdl,
+				      uint64_t samplerate)
 {
 	struct cmd_start_acquisition cmd;
 	int delay = 0, ret;
diff --git a/hardware/fx2lafw/command.h b/hardware/fx2lafw/command.h
index 4dcf0483..cdc9f1eb 100644
--- a/hardware/fx2lafw/command.h
+++ b/hardware/fx2lafw/command.h
@@ -20,6 +20,8 @@
 #ifndef LIBSIGROK_HARDWARE_FX2LAFW_COMMAND_H
 #define LIBSIGROK_HARDWARE_FX2LAFW_COMMAND_H
 
+#include "sigrok.h"
+
 /* Protocol commands */
 #define CMD_GET_FW_VERSION		0xb0
 #define CMD_START			0xb1
@@ -38,7 +40,7 @@ struct cmd_start_acquisition {
 
 #pragma pack(pop)
 
-int command_start_acquisition(libusb_device_handle *devhdl,
-			      uint64_t samplerate);
+SR_PRIV int command_start_acquisition(libusb_device_handle *devhdl,
+				      uint64_t samplerate);
 
 #endif