diff --git a/configure.ac b/configure.ac
index 08a6d4082..6d1758bb3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -73,7 +73,7 @@ AC_ARG_ENABLE(irrlicht, [AS_HELP_STRING(--enable-irrlicht,
                                      [enable irrlicht compilation (still early pre-alpha)])],,
               enable_irrlicht=false)
 if test x$enable_irrlicht = xyes; then
-    AC_DEFINE([HAVE_IRRLICHT], [],  [enable irrlicht compilation])
+    AC_DEFINE([HAVE_IRRLICHT], [1],  [enable irrlicht compilation])
     SUMMARY="$SUMMARY\nCompiling for irrlicht - be warned, pre-alpha!!"
 fi
 
@@ -277,7 +277,7 @@ if test x$enable_irrlicht = xyes; then
    AC_ARG_WITH(irrlicht, [AS_HELP_STRING(--with-irrlicht=PREFIX,
                                    [specify the prefix path to irrlicht])])
    if test "x$with_irrlicht" != "x" ; then
-      CPPFLAGS="${CPPFLAGS} -I $with_irrlicht/include"
+      CPPFLAGS="${CPPFLAGS} -I$with_irrlicht/include/irrlicht"
    fi
    AC_CHECK_HEADER(irrlicht.h, have_irrlicht_hdr=yes)
    dnl how to use irr namespace here?? g++:   'irr' has not been declared
@@ -292,6 +292,12 @@ if test x$enable_irrlicht = xyes; then
    ;;
    esac
 
+   case "${host}" in
+   *darwin*|*macosx*)
+   irrlicht_LIBS="-L/$with_irrlicht/lib/ -lIrrlicht"
+   ;;
+   esac
+
 fi
 
 dnl ======================================================
diff --git a/src/ide/Xcode/STK_XCode.xcodeproj/project.pbxproj b/src/ide/Xcode/STK_XCode.xcodeproj/project.pbxproj
index 0712c33d9..a669eb6fd 100644
--- a/src/ide/Xcode/STK_XCode.xcodeproj/project.pbxproj
+++ b/src/ide/Xcode/STK_XCode.xcodeproj/project.pbxproj
@@ -2556,6 +2556,10 @@
 				GCC_MODEL_TUNING = "";
 				GCC_OPTIMIZATION_LEVEL = 0;
 				GCC_SYMBOLS_PRIVATE_EXTERN = NO;
+				GCC_WARN_UNUSED_FUNCTION = YES;
+				GCC_WARN_UNUSED_LABEL = YES;
+				GCC_WARN_UNUSED_PARAMETER = YES;
+				GCC_WARN_UNUSED_VALUE = YES;
 				HEADER_SEARCH_PATHS = (
 					/usr/local/include,
 					"$(HEADER_SEARCH_PATHS_QUOTED_1)",