diff --git a/make/tool_install/qt-install.qs b/make/tool_install/qt-install.qs
index 0eb07f707..4e98de846 100644
--- a/make/tool_install/qt-install.qs
+++ b/make/tool_install/qt-install.qs
@@ -1,10 +1,10 @@
 /*
 silent installer script
 
-known not work with Qt 5.6.0 and QtIFW 2.1.0
+known to work with Qt 5.6.0 and QtIFW 2.1.0
 
 known issues:
-- silent but not headless (QtIFW 2.0.3 should support installer.setSilent(true))
+- silent but not headless (QtIFW 2.1.0 should support gui.setSilent(true))
 - cannot disable forced components (QtCreator, ...)
  - cannot disable virtual components (doc, examples, ...)
  - cannot disable shortcuts creation
diff --git a/make/tools.mk b/make/tools.mk
index 9222c1921..ec89e5012 100644
--- a/make/tools.mk
+++ b/make/tools.mk
@@ -86,16 +86,16 @@ $(TOOL_REMOVE_TARGETS):
 
 TOOLS_URL := http://librepilot.github.io/tools
 
-QT_MAJOR_VERSION := 5.6
-QT_FULL_VERSION := 5.6.0
+QT_SHORT_VERSION := 5.6
+QT_VERSION := 5.6.0
 
 ifeq ($(UNAME), Linux)
     ifeq ($(ARCH), x86_64)
         QT_SDK_ARCH    := gcc_64
-        QT_SDK_URL     := http://download.qt.io/official_releases/qt/$(QT_MAJOR_VERSION)/$(QT_FULL_VERSION)/qt-opensource-linux-x64-$(QT_FULL_VERSION).run
-        QT_SDK_MD5_URL := http://download.qt.io/official_releases/qt/$(QT_MAJOR_VERSION)/$(QT_FULL_VERSION)/md5sums.txt
-        OSG_URL        := $(TOOLS_URL)/osg-3.5.1-linux-x64-qt-$(QT_FULL_VERSION).tar.gz
-        OSGEARTH_URL   := $(TOOLS_URL)/osgearth-2.7-linux-x64-qt-$(QT_FULL_VERSION).tar.gz
+        QT_SDK_URL     := http://download.qt.io/official_releases/qt/$(QT_SHORT_VERSION)/$(QT_VERSION)/qt-opensource-linux-x64-$(QT_VERSION).run
+        QT_SDK_MD5_URL := http://download.qt.io/official_releases/qt/$(QT_SHORT_VERSION)/$(QT_VERSION)/md5sums.txt
+        OSG_URL        := $(TOOLS_URL)/osg-3.5.1-linux-x64-qt-$(QT_VERSION).tar.gz
+        OSGEARTH_URL   := $(TOOLS_URL)/osgearth-2.7-linux-x64-qt-$(QT_VERSION).tar.gz
     else
 			# x32 for linux no longer provided as pre-built binaries.
     endif
@@ -103,18 +103,18 @@ ifeq ($(UNAME), Linux)
     DOXYGEN_URL    := $(TOOLS_URL)/doxygen-1.8.3.1.src.tar.gz
 else ifeq ($(UNAME), Darwin)
     QT_SDK_ARCH    := clang_64
-    QT_SDK_URL     := http://download.qt.io/official_releases/qt/$(QT_MAJOR_VERSION)/$(QT_FULL_VERSION)/qt-opensource-mac-x64-clang-$(QT_FULL_VERSION).dmg
-    QT_SDK_MD5_URL := http://download.qt.io/official_releases/qt/$(QT_MAJOR_VERSION)/$(QT_FULL_VERSION)/md5sums.txt
-    QT_SDK_MOUNT_DIR        := /Volumes/qt-opensource-mac-x64-clang-$(QT_FULL_VERSION)
-    QT_SDK_MAINTENANCE_TOOL := /Volumes/qt-opensource-mac-x64-clang-$(QT_FULL_VERSION)/qt-opensource-mac-x64-clang-$(QT_FULL_VERSION).app/Contents/MacOS/qt-opensource-mac-x64-clang-$(QT_FULL_VERSION)
+    QT_SDK_URL     := http://download.qt.io/official_releases/qt/$(QT_SHORT_VERSION)/$(QT_VERSION)/qt-opensource-mac-x64-clang-$(QT_VERSION).dmg
+    QT_SDK_MD5_URL := http://download.qt.io/official_releases/qt/$(QT_SHORT_VERSION)/$(QT_VERSION)/md5sums.txt
+    QT_SDK_MOUNT_DIR        := /Volumes/qt-opensource-mac-x64-clang-$(QT_VERSION)
+    QT_SDK_MAINTENANCE_TOOL := /Volumes/qt-opensource-mac-x64-clang-$(QT_VERSION)/qt-opensource-mac-x64-clang-$(QT_VERSION).app/Contents/MacOS/qt-opensource-mac-x64-clang-$(QT_VERSION)
     UNCRUSTIFY_URL := $(TOOLS_URL)/uncrustify-0.60.tar.gz
     DOXYGEN_URL    := $(TOOLS_URL)/doxygen-1.8.3.1.src.tar.gz
-    OSG_URL        := $(TOOLS_URL)/osg-3.5.1-clang_64-qt-$(QT_FULL_VERSION).tar.gz
-    OSGEARTH_URL   := $(TOOLS_URL)/osgearth-2.7-clang_64-qt-$(QT_FULL_VERSION).tar.gz
+    OSG_URL        := $(TOOLS_URL)/osg-3.5.1-clang_64-qt-$(QT_VERSION).tar.gz
+    OSGEARTH_URL   := $(TOOLS_URL)/osgearth-2.7-clang_64-qt-$(QT_VERSION).tar.gz
 else ifeq ($(UNAME), Windows)
     QT_SDK_ARCH    := mingw492_32
-    QT_SDK_URL     := http://download.qt.io/official_releases/qt/$(QT_MAJOR_VERSION)/$(QT_FULL_VERSION)/qt-opensource-windows-x86-mingw492-$(QT_FULL_VERSION).exe
-    QT_SDK_MD5_URL := http://download.qt.io/official_releases/qt/$(QT_MAJOR_VERSION)/$(QT_FULL_VERSION)/md5sums.txt
+    QT_SDK_URL     := http://download.qt.io/official_releases/qt/$(QT_SHORT_VERSION)/$(QT_VERSION)/qt-opensource-windows-x86-mingw492-$(QT_VERSION).exe
+    QT_SDK_MD5_URL := http://download.qt.io/official_releases/qt/$(QT_SHORT_VERSION)/$(QT_VERSION)/md5sums.txt
     NSIS_URL       := $(TOOLS_URL)/nsis-2.46-unicode.tar.bz2
     MESAWIN_URL    := $(TOOLS_URL)/mesawin.tar.gz
     UNCRUSTIFY_URL := $(TOOLS_URL)/uncrustify-0.60-windows.tar.bz2
@@ -125,7 +125,6 @@ GTEST_URL 	   := $(TOOLS_URL)/gtest-1.7.0.zip
 CCACHE_URL     := http://samba.org/ftp/ccache/ccache-3.2.2.tar.bz2
 CCACHE_MD5_URL := $(TOOLS_URL)/ccache-3.2.2.tar.bz2.md5
 
-QT_VERSION     := $(QT_FULL_VERSION)
 QT_SDK_DIR     := $(TOOLS_DIR)/qt-$(QT_VERSION)
 UNCRUSTIFY_DIR := $(TOOLS_DIR)/uncrustify-0.60
 DOXYGEN_DIR    := $(TOOLS_DIR)/doxygen-1.8.3.1
@@ -512,17 +511,17 @@ endef
 
 ifeq ($(UNAME), Windows)
 
-    QT_SDK_PREFIX := $(QT_SDK_DIR)/$(QT_MAJOR_VERSION)/$(QT_SDK_ARCH)
+    QT_SDK_PREFIX := $(QT_SDK_DIR)/$(QT_SHORT_VERSION)/$(QT_SDK_ARCH)
     $(eval $(call QT_INSTALL_TEMPLATE,$(QT_SDK_DIR),$(QT_SDK_URL),$(QT_SDK_MD5_URL),$(notdir $(QT_SDK_URL)),$(QT_SDK_ARCH)))
 
 else ifeq ($(UNAME), Linux)
 
-    QT_SDK_PREFIX := "$(QT_SDK_DIR)/$(QT_MAJOR_VERSION)/$(QT_SDK_ARCH)"
+    QT_SDK_PREFIX := "$(QT_SDK_DIR)/$(QT_SHORT_VERSION)/$(QT_SDK_ARCH)"
     $(eval $(call QT_INSTALL_TEMPLATE,$(QT_SDK_DIR),$(QT_SDK_URL),$(QT_SDK_MD5_URL),$(notdir $(QT_SDK_URL)),$(QT_SDK_ARCH)))
 
 else ifeq ($(UNAME), Darwin)
 
-    QT_SDK_PREFIX := "$(QT_SDK_DIR)/$(QT_MAJOR_VERSION)/$(QT_SDK_ARCH)"
+    QT_SDK_PREFIX := "$(QT_SDK_DIR)/$(QT_SHORT_VERSION)/$(QT_SDK_ARCH)"
     $(eval $(call MAC_QT_INSTALL_TEMPLATE,$(QT_SDK_DIR),$(QT_SDK_URL),$(QT_SDK_MD5_URL),$(notdir $(QT_SDK_URL)),$(QT_SDK_ARCH)))
 
 else