diff --git a/configure b/configure
index e9ddba85d4..ee4f2cea75 100755
--- a/configure
+++ b/configure
@@ -33566,9 +33566,6 @@ if test "$wxUSE_MOUSEWHEEL" = "yes" ; then
 fi
 
 if test "$wxUSE_UIACTIONSIMULATOR" = "yes" ; then
-    $as_echo "#define wxUSE_UIACTIONSIMULATOR 1" >>confdefs.h
-
-    SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS uiaction"
     if test "$wxUSE_GTK" = 1 -o "$wxUSE_MOTIF" = 1 -o "$wxUSE_X11" = 1; then
         if test "$wxUSE_XTEST" = "yes" ; then
 
@@ -33631,16 +33628,22 @@ fi
 	echo "$XTST_PKG_ERRORS" >&5
 
 
-                    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: XTest extension not found" >&5
-$as_echo "$as_me: WARNING: XTest extension not found" >&2;}
-                    wxUSE_XTEST="no"
+                    if test "$WXGTK3" = 1; then
+                                                                        { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: XTest not found, disabling wxUIActionSimulator" >&5
+$as_echo "$as_me: WARNING: XTest not found, disabling wxUIActionSimulator" >&2;}
+                        wxUSE_UIACTIONSIMULATOR=no
+                    fi
+                                        wxUSE_XTEST="no"
 
 
 elif test $pkg_failed = untried; then
 
-                    { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: XTest extension not found" >&5
-$as_echo "$as_me: WARNING: XTest extension not found" >&2;}
-                    wxUSE_XTEST="no"
+                    if test "$WXGTK3" = 1; then
+                                                                        { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: XTest not found, disabling wxUIActionSimulator" >&5
+$as_echo "$as_me: WARNING: XTest not found, disabling wxUIActionSimulator" >&2;}
+                        wxUSE_UIACTIONSIMULATOR=no
+                    fi
+                                        wxUSE_XTEST="no"
 
 
 else
@@ -33658,6 +33661,12 @@ $as_echo "yes" >&6; }
 fi
         fi
     fi
+
+    if test "$wxUSE_UIACTIONSIMULATOR" = "yes" ; then
+        $as_echo "#define wxUSE_UIACTIONSIMULATOR 1" >>confdefs.h
+
+        SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS uiaction"
+    fi
 fi
 
 if test "$wxUSE_DC_TRANSFORM_MATRIX" = "yes" ; then
diff --git a/configure.in b/configure.in
index b71b16a182..ffa2ab839e 100644
--- a/configure.in
+++ b/configure.in
@@ -6359,8 +6359,6 @@ if test "$wxUSE_MOUSEWHEEL" = "yes" ; then
 fi
 
 if test "$wxUSE_UIACTIONSIMULATOR" = "yes" ; then
-    AC_DEFINE(wxUSE_UIACTIONSIMULATOR)
-    SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS uiaction"
     if test "$wxUSE_GTK" = 1 -o "$wxUSE_MOTIF" = 1 -o "$wxUSE_X11" = 1; then
         if test "$wxUSE_XTEST" = "yes" ; then
             PKG_CHECK_MODULES(XTST, xtst,
@@ -6371,12 +6369,23 @@ if test "$wxUSE_UIACTIONSIMULATOR" = "yes" ; then
                     AC_DEFINE(wxUSE_XTEST)
                 ],
                 [
-                    AC_MSG_WARN([XTest extension not found])
+                    if test "$WXGTK3" = 1; then
+                        dnl This class can't work without XTest with GTK+ 3
+                        dnl which uses XInput2 and so ignores XSendEvent().
+                        AC_MSG_WARN([XTest not found, disabling wxUIActionSimulator])
+                        wxUSE_UIACTIONSIMULATOR=no
+                    fi
+                    dnl The other ports can use XSendEvent(), so don't warn
                     wxUSE_XTEST="no"
                 ]
             )
         fi
     fi
+
+    if test "$wxUSE_UIACTIONSIMULATOR" = "yes" ; then
+        AC_DEFINE(wxUSE_UIACTIONSIMULATOR)
+        SAMPLES_SUBDIRS="$SAMPLES_SUBDIRS uiaction"
+    fi
 fi
 
 if test "$wxUSE_DC_TRANSFORM_MATRIX" = "yes" ; then