diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 93d574faf1fe..375cd6e4aade 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -136,6 +136,7 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 		caps.pps = ptp->info->pps;
 		caps.n_pins = ptp->info->n_pins;
 		caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
+		caps.adjust_phase = ptp->info->adjphase != NULL;
 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 			err = -EFAULT;
 		break;
diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h
index 9dc9d0079e98..ff070aa64278 100644
--- a/include/uapi/linux/ptp_clock.h
+++ b/include/uapi/linux/ptp_clock.h
@@ -89,7 +89,9 @@ struct ptp_clock_caps {
 	int n_pins;    /* Number of input/output pins. */
 	/* Whether the clock supports precise system-device cross timestamps */
 	int cross_timestamping;
-	int rsv[13];   /* Reserved for future use. */
+	/* Whether the clock supports adjust phase */
+	int adjust_phase;
+	int rsv[12];   /* Reserved for future use. */
 };
 
 struct ptp_extts_request {
diff --git a/tools/testing/selftests/ptp/testptp.c b/tools/testing/selftests/ptp/testptp.c
index c0dd10257df5..da7a9dda9490 100644
--- a/tools/testing/selftests/ptp/testptp.c
+++ b/tools/testing/selftests/ptp/testptp.c
@@ -269,14 +269,16 @@ int main(int argc, char *argv[])
 			       "  %d programmable periodic signals\n"
 			       "  %d pulse per second\n"
 			       "  %d programmable pins\n"
-			       "  %d cross timestamping\n",
+			       "  %d cross timestamping\n"
+			       "  %d adjust_phase\n",
 			       caps.max_adj,
 			       caps.n_alarm,
 			       caps.n_ext_ts,
 			       caps.n_per_out,
 			       caps.pps,
 			       caps.n_pins,
-			       caps.cross_timestamping);
+			       caps.cross_timestamping,
+			       caps.adjust_phase);
 		}
 	}