diff --git a/qemu-doc.texi b/qemu-doc.texi
index 0e0e0ae72b..057a48ec1f 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -2922,6 +2922,11 @@ The @code{-startdate} option has been replaced by @code{-rtc base=@var{date}}.
 Option @option{-virtioconsole} has been replaced by
 @option{-device virtconsole}.
 
+@subsection -clock (since 3.0.0)
+
+The @code{-clock} option is ignored since QEMU version 1.7.0. There is no
+replacement since it is not needed anymore.
+
 @section qemu-img command line arguments
 
 @subsection convert -s (since 2.0.0)
diff --git a/vl.c b/vl.c
index 4a0e17833d..c70ce25de7 100644
--- a/vl.c
+++ b/vl.c
@@ -3713,6 +3713,7 @@ int main(int argc, char **argv, char **envp)
                 /* Clock options no longer exist.  Keep this option for
                  * backward compatibility.
                  */
+                warn_report("This option is ignored and will be removed soon");
                 break;
             case QEMU_OPTION_startdate:
                 warn_report("This option is deprecated, use '-rtc base=' instead.");