diff --git a/CMakeModules/CompilerFlags.cmake b/CMakeModules/CompilerFlags.cmake
index 46e1a27..97dd974 100644
--- a/CMakeModules/CompilerFlags.cmake
+++ b/CMakeModules/CompilerFlags.cmake
@@ -1,6 +1,15 @@
 # MSVC goes totally bananas if we pass it -Wall
 if(NOT MSVC)
   enable_if_supported(COMPILER_FLAGS "-Wall")
+  enable_if_supported(COMPILER_FLAGS "-Wextra")
+  enable_if_supported(COMPILER_FLAGS "-Wformat")
+  enable_if_supported(COMPILER_FLAGS "-Werror=format-security")
+  enable_if_supported(COMPILER_FLAGS "-Wshadow")
+  enable_if_supported(COMPILER_FLAGS "-Wundef")
+  enable_if_supported(COMPILER_FLAGS "-Wcast-align")
+  enable_if_supported(COMPILER_FLAGS "-Wmissing-include-dirs")
+  enable_if_supported(COMPILER_FLAGS "-Woverloaded-virtual")
+  enable_if_supported(COMPILER_FLAGS "-Wold-style-cast")
 endif()
 
 enable_if_supported(COMPILER_FLAGS "-Wshorten-64-to-32")
diff --git a/CMakeModules/QtConfiguration.cmake b/CMakeModules/QtConfiguration.cmake
index b5ebb7e..6a8dd16 100644
--- a/CMakeModules/QtConfiguration.cmake
+++ b/CMakeModules/QtConfiguration.cmake
@@ -17,7 +17,7 @@ message(STATUS "Qt root directory: ${QTROOT}")
 
 list(APPEND CMAKE_FIND_ROOT_PATH ${QTROOT})
 list(APPEND CMAKE_PREFIX_PATH ${QTROOT})
-if(NOT "${QTROOT}" STREQUAL "")
+if(IS_DIRECTORY "${QTROOT}/include")
   include_directories(${QTROOT}/include)
 endif()