diff --git a/build_num b/build_num
deleted file mode 100644
index 66c4ca9ed..000000000
--- a/build_num
+++ /dev/null
@@ -1 +0,0 @@
-#define BUILD_NUM 3407
diff --git a/qmake.inc.in b/qmake.inc.in
index d035f6655..230bd7872 100644
--- a/qmake.inc.in
+++ b/qmake.inc.in
@@ -83,4 +83,15 @@ exists(qmake2.inc) {
   include(qmake2.inc)
 }
 
+exists(build_num) {
+	include(build_num)
+}
+if (isEmpty(BUILD_NUM)) {
+	GIT_BRANCH=$$system(git branch | grep '\\*' | cut -c3-)
+	GIT_COMMIT=$$system(git show --abbrev-commit -1 --pretty=oneline --shortstat | head -1 | cut -c1-7)
+	BUILD_NUM="$$GIT_BRANCH:$$GIT_COMMIT"
+}
+
+DEFINES += BUILD_NUM=$$BUILD_NUM
+
 INSTALLS += target
diff --git a/src/common/init.cpp b/src/common/init.cpp
index 2be7b8318..b27201ae0 100644
--- a/src/common/init.cpp
+++ b/src/common/init.cpp
@@ -1,7 +1,6 @@
 
 
 #include "../../config.h"
-#include "../../build_num"
 
 #include <string>
 #include <assert.h>
diff --git a/src/libgui/libgui.pro b/src/libgui/libgui.pro
index f886873e0..6a41eee98 100644
--- a/src/libgui/libgui.pro
+++ b/src/libgui/libgui.pro
@@ -26,7 +26,6 @@ INSTALLS -= target
 # control whether we build debug or release in ../../qmake.inc
 # CONFIG += precompile_header
 HEADERS += ../../config.h \
-    ../../build_num \
     events.h \
     FWWindow.h \
     ProjectPanel.h \