diff --git a/configure b/configure
index e28f381297..2f7c537ee5 100755
--- a/configure
+++ b/configure
@@ -4635,9 +4635,11 @@ if [ "$CFG_LIBUDEV" != "no" ]; then
         exit 1
     else
         CFG_LIBUDEV=no
-        QMakeVar add DEFINES QT_NO_LIBUDEV
     fi
 fi
+if [ "$CFG_LIBUDEV" = "no" ]; then
+    QMakeVar add DEFINES QT_NO_LIBUDEV
+fi
 
 if [ "$CFG_EVDEV" != "no" ]; then
     if "$unixtests/compile.test" "$XQMAKESPEC" "$QMAKE_CONFIG" $OPT_VERBOSE "$relpath" "$outpath" config.tests/unix/evdev "evdev" $L_FLAGS $I_FLAGS $D_FLAGS $l_FLAGS; then
@@ -4648,9 +4650,11 @@ if [ "$CFG_EVDEV" != "no" ]; then
         exit 1
     else
         CFG_EVDEV=no
-        QMakeVar add DEFINES QT_NO_EVDEV
     fi
 fi
+if [ "$CFG_EVDEV" = "no" ]; then
+    QMakeVar add DEFINES QT_NO_EVDEV
+fi
 
 # Check we actually have X11 :-)
 if "$unixtests/compile.test" "$XQMAKESPEC" "$QMAKE_CONFIG" $OPT_VERBOSE "$relpath" "$outpath" config.tests/x11/xlib "XLib" $L_FLAGS $I_FLAGS $D_FLAGS $l_FLAGS; then
@@ -4720,9 +4724,11 @@ if [ "$CFG_XCB" != "no" ]; then
             exit 1
         fi
         CFG_XCB=no
-        QMakeVar add DEFINES QT_NO_XCB
     fi
 fi
+if [ "$CFG_XCB" = "no" ]; then
+    QMakeVar add DEFINES QT_NO_XCB
+fi
 
 if [ "$CFG_DIRECTFB" != "no" ]; then
     if [ -n "$PKG_CONFIG" ] && $PKG_CONFIG --exists directfb 2>/dev/null; then