diff --git a/Tools/Replay/LogReader.cpp b/Tools/Replay/LogReader.cpp
index c8f7bc2c23..c655798966 100644
--- a/Tools/Replay/LogReader.cpp
+++ b/Tools/Replay/LogReader.cpp
@@ -26,6 +26,7 @@
 #include "MsgHandler_IMU3.h"
 #include "MsgHandler_SIM.h"
 #include "MsgHandler_BARO.h"
+#include "MsgHandler_ARM.h"
 #include "MsgHandler_AHR2.h"
 #include "MsgHandler_ATT.h"
 #include "MsgHandler_MAG.h"
@@ -120,6 +121,8 @@ bool LogReader::update(char type[5])
 	memcpy(name, f.name, 4);
 	::printf("Defining log format for type (%d) (%s)\n", f.type, name);
 
+        dataflash.WriteBlock(&f, sizeof(f));
+
 	// map from format name to a parser subclass:
 	if (streq(name, "PARM")) {
             parameter_handler = new MsgHandler_PARM(formats[f.type], dataflash,
@@ -159,6 +162,9 @@ bool LogReader::update(char type[5])
 	} else if (streq(name, "BARO")) {
 	  msgparser[f.type] = new MsgHandler_BARO(formats[f.type], dataflash,
                                                   last_timestamp_usec, baro);
+	} else if (streq(name, "ARM")) {
+	  msgparser[f.type] = new MsgHandler_ARM(formats[f.type], dataflash,
+                                                  last_timestamp_usec);
 	} else if (streq(name, "AHR2")) {
 	  msgparser[f.type] = new MsgHandler_AHR2(formats[f.type], dataflash,
 						  last_timestamp_usec,
diff --git a/Tools/Replay/MsgHandler_ARM.cpp b/Tools/Replay/MsgHandler_ARM.cpp
new file mode 100644
index 0000000000..5522655ab2
--- /dev/null
+++ b/Tools/Replay/MsgHandler_ARM.cpp
@@ -0,0 +1,14 @@
+#include "MsgHandler_ARM.h"
+
+extern const AP_HAL::HAL& hal;
+
+void MsgHandler_ARM::process_message(uint8_t *msg)
+{
+    wait_timestamp_from_msg(msg);
+    uint8_t ArmState = require_field_uint8_t(msg, "ArmState");
+    hal.util->set_soft_armed(ArmState);
+    printf("Armed state: %u at %lu\n", 
+           (unsigned)ArmState,
+           (unsigned long)hal.scheduler->millis());
+    dataflash.WriteBlock(msg, f.length);
+}
diff --git a/Tools/Replay/MsgHandler_ARM.h b/Tools/Replay/MsgHandler_ARM.h
new file mode 100644
index 0000000000..f3b429b694
--- /dev/null
+++ b/Tools/Replay/MsgHandler_ARM.h
@@ -0,0 +1,11 @@
+#include "MsgHandler.h"
+
+class MsgHandler_ARM : public MsgHandler
+{
+public:
+    MsgHandler_ARM(log_Format &_f, DataFlash_Class &_dataflash,
+                   uint64_t &_last_timestamp_usec)
+        : MsgHandler(_f, _dataflash, _last_timestamp_usec) { };
+
+    virtual void process_message(uint8_t *msg);
+};