diff --git a/BUILD.md b/BUILD.md
index e033916e08..8f871c3cea 100644
--- a/BUILD.md
+++ b/BUILD.md
@@ -38,7 +38,7 @@ Any variables that need to be set for CMake to find dependencies can be set as E
 
 For example, to pass the QT_CMAKE_PREFIX_PATH variable during build file generation:
 
-    cmake .. -DQT_CMAKE_PREFIX_PATH=/usr/local/qt/5.2.0/clang_64/lib/cmake
+    cmake .. -DQT_CMAKE_PREFIX_PATH=/usr/local/qt/5.2.0/lib/cmake
 
 
 UNIX
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4674df40de..cb1e4224cf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,11 @@ elseif (CMAKE_COMPILER_IS_GNUCC OR CMAKE_COMPILER_IS_GNUCXX)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall")
 endif(WIN32)
 
-set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} $ENV{QT_CMAKE_PREFIX_PATH})
+if (NOT QT_CMAKE_PREFIX_PATH)
+  set(QT_CMAKE_PREFIX_PATH $ENV{QT_CMAKE_PREFIX_PATH})
+endif ()
+
+set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} ${QT_CMAKE_PREFIX_PATH})
 
 # set our Base SDK to 10.8
 set(CMAKE_OSX_SYSROOT /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk)