diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1824861d3..4af5d2b55 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -334,7 +334,7 @@ include_directories(${OPENSCENEGRAPH_INCLUDE_DIRS}
     ${ZLIB_INCLUDE_DIR}
     ${OPENGL_INCLUDE_DIR}
     ${OPENAL_INCLUDE_DIR}
-    ${SIMGEAR_INCLUDE_DIR}
+    ${SIMGEAR_INCLUDE_DIRS}
     ${PLIB_INCLUDE_DIR}
     ${SQLITE3_INCLUDED_DIR} )
 
diff --git a/CMakeModules/FindSimGear.cmake b/CMakeModules/FindSimGear.cmake
index 56f230a88..1cadbe201 100644
--- a/CMakeModules/FindSimGear.cmake
+++ b/CMakeModules/FindSimGear.cmake
@@ -4,7 +4,7 @@
 # SIMGEAR_CORE_LIBRARIES, a list of the core static libraries
 # SIMGEAR_LIBRARIES, a list of all the static libraries (core + scene)
 # SIMGEAR_FOUND, if false, do not try to link to SimGear
-# SIMGEAR_INCLUDE_DIR, where to find the headers
+# SIMGEAR_INCLUDE_DIRS, where to find the headers
 #
 # $SIMGEAR_DIR is an environment variable that would
 # correspond to the ./configure --prefix=$SIMGEAR_DIR
@@ -180,7 +180,11 @@ endif()
 # now we've found SimGear, try test-compiling using its includes
 include(CheckCXXSourceRuns)
 
-SET(CMAKE_REQUIRED_INCLUDES ${SIMGEAR_INCLUDE_DIR})
+set(SIMGEAR_INCLUDE_DIRS
+  ${SIMGEAR_INCLUDE_DIR}
+  ${SIMGEAR_INCLUDE_DIR}/simgear/3rdparty/utf8
+)
+SET(CMAKE_REQUIRED_INCLUDES ${SIMGEAR_INCLUDE_DIRS})
 
 # clear cache, run a fresh compile test every time
 unset(SIMGEAR_COMPILE_TEST CACHE)
@@ -226,5 +230,5 @@ unset(CMAKE_REQUIRED_DEFINITIONS)
 
 include(FindPackageHandleStandardArgs)
 FIND_PACKAGE_HANDLE_STANDARD_ARGS(SimGear DEFAULT_MSG
-     SIMGEAR_LIBRARIES SIMGEAR_CORE_LIBRARIES SIMGEAR_INCLUDE_DIR SIMGEAR_COMPILE_TEST)
+     SIMGEAR_LIBRARIES SIMGEAR_CORE_LIBRARIES SIMGEAR_INCLUDE_DIRS SIMGEAR_COMPILE_TEST)