diff -purN dillo-2.2.orig/configure dillo-2.2/configure
--- dillo-2.2.orig/configure	2010-02-18 09:10:13.000000000 +0100
+++ dillo-2.2/configure	2010-02-18 09:13:20.000000000 +0100
@@ -6059,6 +6059,7 @@ fi
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking FLTK2" >&5
 $as_echo_n "checking FLTK2... " >&6; }
+if test "x$LIBFLTK_LIBS" = "x" && test "x$LIBFLTK_CFLAGS" != "x"; then
 if sh -c "fltk2-config --version" >/dev/null 2>&1
 then { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
@@ -6069,7 +6070,7 @@ else { $as_echo "$as_me:${as_lineno-$LIN
 $as_echo "no" >&6; }
      as_fn_error "FLTK2 must be installed!" "$LINENO" 5
 fi
-
+fi
 
 if test "x$enable_jpeg" = "xyes"; then
   ac_fn_c_check_header_mongrel "$LINENO" "jpeglib.h" "ac_cv_header_jpeglib_h" "$ac_includes_default"