diff --git a/configure b/configure
index 62dce59..216b710 100755
--- a/configure
+++ b/configure
@@ -27,6 +27,11 @@ usageoptions()
 usage()
 {
     local r="$1"
+    s=
+    if test $has_skalibs -eq 1; then
+        s="
+      --sysdeps=DIR                 Use skalibs' sysdeps from DIR [LIBDIR/skalibs/sysdeps]"
+    fi
     cat <<EOF
 usage: $0 [OPTION..]
 
@@ -37,8 +42,7 @@ usage: $0 [OPTION..]
       --libdir=DIR                  Set library directory to DIR [PREFIX/lib]
       --incdir=DIR                  Set include directory to DIR [PREFIX/include]
       --sharedir=DIR                Set share directory to DIR [PREFIX/share]
-
-      --sysdeps=DIR                 Use skalibs' sysdeps from DIR [LIBDIR/skalibs/sysdeps]
+$s
       --prefer-shared               Prefer to link shared libraires [default]
       --prefer-static               Prefer to link static libraires
       --set-shared=DEP              Use shared linking for dependency DEP
@@ -63,6 +67,9 @@ libdir=
 incdir=
 sharedir=
 
+# this isn't quite right, since skalibs could be optional, but it'll do.
+has_skalibs=0
+if test -d meta/deps/skalibs; then has_skalibs=1; fi
 sysdeps=
 prefer=shared
 
@@ -88,7 +95,8 @@ for arg ; do
         --incdir=*) incdir=${arg#*=} ;;
         --sharedir=*) sharedir=${arg#*=} ;;
 
-        --sysdeps=*) sysdeps=${arg#*=} ;;
+        --sysdeps=*) if test $has_skalibs -eq 1; then sysdeps=${arg#*=};
+        else error 1 "invalid option '$arg'"; fi;;
         --prefer-shared) ;;
         --prefer-static) prefer=static ;;
         --set-shared=*) eval "link${arg#*=}=1" ;;
@@ -367,24 +375,25 @@ trycmd AR "ar"
 trycmd RANLIB "$RANLIB"
 trycmd RANLIB "ranlib"
 
-echo " => Checking sysdeps... $sysdeps"
-echon "  -> Checking target.."
-if test -z "$target" ; then
-    target=$($CC -dumpmachine 2>/dev/null) || target=unknown
-fi
-BITS=32
-case "$target" in
-    *x86_64*) BITS=64 ;;
-esac
-echo ".. $target [${BITS}bit]"
-if test ! -d $sysdeps || test ! -f $sysdeps/target; then
-    error 2 "$sysdeps is not a valid sysdeps directory"
-fi
-if test "x$target" != "x$(cat $sysdeps/target)"; then
-    error 2 "target $target does not match the contents of $sysdeps/target ($(cat $sysdeps/target))"
+if test $has_skalibs -eq 1; then
+    echo " => Checking sysdeps... $sysdeps"
+    echon "  -> Checking target.."
+    if test -z "$target" ; then
+        target=$($CC -dumpmachine 2>/dev/null) || target=unknown
+    fi
+    BITS=32
+    case "$target" in
+        *x86_64*) BITS=64 ;;
+    esac
+    echo ".. $target [${BITS}bit]"
+    if test ! -d $sysdeps || test ! -f $sysdeps/target; then
+        error 2 "$sysdeps is not a valid sysdeps directory"
+    fi
+    if test "x$target" != "x$(cat $sysdeps/target)"; then
+        error 2 "target $target does not match the contents of $sysdeps/target ($(cat $sysdeps/target))"
+    fi
 fi
 
-
 echo " => Testing C compiler..."
 tryflag CFLAGS -std=c99
 tryflag CFLAGS -fomit-frame-pointer
@@ -435,8 +444,10 @@ echo "# $0 $@"
 echo "# Any changes you make in here will be lost on the next ./configure"
 echo ""
 
-echo "BITS := $BITS"
-echo ""
+if test -n "$BITS"; then
+    echo "BITS := $BITS"
+    echo ""
+fi
 
 echo "CC = $CC"
 echo "AR = $AR"
@@ -553,7 +564,6 @@ cat <<EOF
 #ifndef ${prefix}_CONFIG_H
 #define ${prefix}_CONFIG_H
 
-#define ${prefix}_BITS      $BITS
 #define ${prefix}_CURYEAR   "$(date +%Y)"
 #define ${prefix}_AUTHOR    "Olivier Brunel"
 #define ${prefix}_VERSION   "$version"