--- VirtualBox-5.0.0_BETA3/configure
+++ VirtualBox-5.0.0_BETA3/configure
@@ -1258,10 +1258,7 @@
   XCloseDisplay(dpy);
 }
 EOF
-  [ -n "$INCX11" ] && I_INCX11=`prefix_I "$INCX11"`
-  if test_compile "$LIBX11 $I_INCX11" Xlibs Xlibs; then
-    log_success "found"
-  fi
+  test_compile "$LIBX11 $I_INCX11" Xlibs Xlibs
 }
 
 
@@ -1415,21 +1412,6 @@
 #include <GL/glu.h>
 extern "C" int main(void)
 {
-  Display *dpy;
-  int major, minor;
-
-  dpy = XOpenDisplay(NULL);
-  if (dpy)
-  {
-    Bool glx_version = glXQueryVersion(dpy, &major, &minor);
-    XCloseDisplay(dpy);
-    if (glx_version)
-    {
-      printf("found version %u.%u, OK.\n", major, minor);
-      return 0;
-    }
-  }
-  printf("found (inactive), OK.\n");
   return 0;
 }
 EOF
@@ -2706,7 +2688,6 @@
   # don't check for yasm for the time beeing as 0.40 and 0.50 both have known bugs
   # [ "$OS" != "darwin" ] && check_yasm
   [ "$OS" != "darwin"  ] && check_xsltproc
-  [ "$OS" != "darwin"  ] && check_mkisofs
 fi
 
 # the libraries
@@ -2774,7 +2755,6 @@
   check_compiler_h
   [ $ONLY_ADDITIONS -eq 0 -a "$BUILD_MACHINE" = "amd64" -a $WITH_VMMRAW -eq 1 ] && check_32bit
   # tools/common/makeself*
-  [ $OSE -ge 1 ] && check_makeself
 fi
 
 [ -n "$SETUP_WINE" ] && setup_wine
