diff --git a/Tools/scripts/add_git_hashes.py b/Tools/scripts/add_git_hashes.py
new file mode 100755
index 0000000000..a25541381c
--- /dev/null
+++ b/Tools/scripts/add_git_hashes.py
@@ -0,0 +1,56 @@
+#!/usr/bin/env python
+'''
+Add git hashes to .px4 file for PX4/Pixhawk build
+Written by Jon Challinger January 2015
+'''
+
+import json
+import sys
+import os
+import subprocess
+import argparse
+
+parser = argparse.ArgumentParser()
+
+parser.add_argument('input_file')
+parser.add_argument('output_file')
+
+parser.add_argument('--ardupilot')
+parser.add_argument('--px4')
+parser.add_argument('--nuttx')
+parser.add_argument('--uavcan')
+
+args = parser.parse_args()
+
+f = open(args.input_file,'r')
+fw_json = json.load(f)
+f.close()
+
+if args.ardupilot is not None:
+    try:
+        fw_json["ardupilot_git_hash"] = subprocess.check_output(["git", "--git-dir", os.path.join(args.ardupilot,".git"), "rev-parse", "HEAD"]).strip().decode('ascii')
+    except:
+        print("Failed to get apm hash")
+        
+if args.px4 is not None:
+    try:
+        fw_json["px4_git_hash"] = subprocess.check_output(["git", "--git-dir", os.path.join(args.px4,".git"), "rev-parse", "HEAD"]).strip().decode('ascii')
+    except:
+        print("Failed to get px4 hash")
+
+if args.nuttx is not None:
+    try:
+        fw_json["nuttx_git_hash"] = subprocess.check_output(["git", "--git-dir", os.path.join(args.nuttx,".git"), "rev-parse", "HEAD"]).strip().decode('ascii')
+    except:
+        print("Failed to get nuttx hash")
+
+if args.uavcan is not None:
+    try:
+        fw_json["uavcan_git_hash"] = subprocess.check_output(["git", "--git-dir", os.path.join(args.uavcan,".git"), "rev-parse", "HEAD"]).strip().decode('ascii')
+    except:
+        print("Failed to get uavcan hash")
+
+f=open(args.output_file,'w')
+json.dump(fw_json,f,indent=4)
+f.truncate()
+f.close()
diff --git a/mk/px4_targets.mk b/mk/px4_targets.mk
index 857fc95978..1e72d9f538 100644
--- a/mk/px4_targets.mk
+++ b/mk/px4_targets.mk
@@ -53,6 +53,18 @@ export GIT_SUBMODULES_ARE_EVIL = 1
 PX4_MAKE = $(v) GIT_SUBMODULES_ARE_EVIL=1 make -C $(SKETCHBOOK) -f $(PX4_ROOT)/Makefile EXTRADEFINES="$(SKETCHFLAGS) $(WARNFLAGS) "'$(EXTRAFLAGS)' APM_MODULE_DIR=$(SKETCHBOOK) SKETCHBOOK=$(SKETCHBOOK) CCACHE=$(CCACHE) PX4_ROOT=$(PX4_ROOT) NUTTX_SRC=$(NUTTX_SRC) MAXOPTIMIZATION="-Os" UAVCAN_DIR=$(UAVCAN_DIR)
 PX4_MAKE_ARCHIVES = make -C $(PX4_ROOT) NUTTX_SRC=$(NUTTX_SRC) CCACHE=$(CCACHE) archives MAXOPTIMIZATION="-Os" 
 
+HASHADDER_FLAGS += --ardupilot "$(SKETCHBOOK)"
+
+ifneq ($(wildcard $(PX4_ROOT)),)
+HASHADDER_FLAGS += --px4 "$(PX4_ROOT)"
+endif
+ifneq ($(wildcard $(NUTTX_SRC)/..),)
+HASHADDER_FLAGS += --nuttx "$(NUTTX_SRC)/.."
+endif
+ifneq ($(wildcard $(UAVCAN_DIR)),)
+HASHADDER_FLAGS += --uavcan "$(UAVCAN_DIR)"
+endif
+
 .PHONY: module_mk
 module_mk:
 	$(RULEHDR)
@@ -70,6 +82,7 @@ px4-v1: $(BUILDROOT)/make.flags $(PX4_ROOT)/Archives/px4fmu-v1.export $(SKETCHCP
 	$(v) $(PX4_MAKE) px4fmu-v1_APM
 	$(v) /bin/rm -f $(SKETCH)-v1.px4
 	$(v) cp $(PX4_ROOT)/Images/px4fmu-v1_APM.px4 $(SKETCH)-v1.px4
+	$(v) $(SKETCHBOOK)/Tools/scripts/add_git_hashes.py $(HASHADDER_FLAGS) "$(SKETCH)-v1.px4" "$(SKETCH)-v1.px4"
 	$(v) echo "PX4 $(SKETCH) Firmware is in $(SKETCH)-v1.px4"
 
 px4-v2: $(BUILDROOT)/make.flags $(PX4_ROOT)/Archives/px4fmu-v2.export $(SKETCHCPP) module_mk px4-io-v2
@@ -79,6 +92,7 @@ px4-v2: $(BUILDROOT)/make.flags $(PX4_ROOT)/Archives/px4fmu-v2.export $(SKETCHCP
 	$(PX4_MAKE) px4fmu-v2_APM
 	$(v) /bin/rm -f $(SKETCH)-v2.px4
 	$(v) cp $(PX4_ROOT)/Images/px4fmu-v2_APM.px4 $(SKETCH)-v2.px4
+	$(v) $(SKETCHBOOK)/Tools/scripts/add_git_hashes.py $(HASHADDER_FLAGS) "$(SKETCH)-v2.px4" "$(SKETCH)-v2.px4"
 	$(v) echo "PX4 $(SKETCH) Firmware is in $(SKETCH)-v2.px4"
 
 px4: px4-v1 px4-v2