Original Author: Johannes Frankenau
https://github.com/i3/i3lock/commit/4d85b886fc16376c85c9ea444ca6b9c0a65cccc5

diff --git a/i3lock.1 b/i3lock.1
index 55af52d..0f00e20 100644
--- a/i3lock.1
+++ b/i3lock.1
@@ -28,6 +28,7 @@ i3lock \- improved screen locker
 .RB [\|\-u\|]
 .RB [\|\-e\|]
 .RB [\|\-f\|]
+.RB [\|\-m\|]
 
 .SH DESCRIPTION
 .B i3lock
@@ -105,6 +106,11 @@ your computer with the enter key.
 .B \-f, \-\-show-failed-attempts
 Show the number of failed attempts, if any.
 
+.TP
+.B \-m, \-\-pass-media-keys
+Allow the following keys to be used while the screen is locked by passing them through:
+XF86AudioPlay, XF86AudioPause, XF86AudioStop, XF86AudioPrev, XF86AudioNext, XF86AudioMute, XF86AudioLowerVolume, XF86AudioRaiseVolume.
+
 .TP
 .B \-\-debug
 Enables debug logging.
diff --git a/i3lock.c b/i3lock.c
index 87a77b1..7b787fa 100644
--- a/i3lock.c
+++ b/i3lock.c
@@ -15,6 +15,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <xcb/xcb.h>
+#include <xcb/xproto.h>
 #include <xcb/xkb.h>
 #include <err.h>
 #include <assert.h>
@@ -89,6 +90,7 @@ cairo_surface_t *img = NULL;
 bool tile = false;
 bool ignore_empty_password = false;
 bool skip_repeated_empty_password = false;
+bool pass_media_keys = false;
 
 /* isutf, u8_dec © 2005 Jeff Bezanson, public domain */
 #define isutf(c) (((c)&0xC0) != 0x80)
@@ -413,6 +415,21 @@ static void handle_key_press(xcb_key_press_event_t *event) {
         n = xkb_keysym_to_utf8(ksym, buffer, sizeof(buffer));
     }
 
+    if (pass_media_keys) {
+        switch (ksym) {
+            case XKB_KEY_XF86AudioPlay:
+            case XKB_KEY_XF86AudioPause:
+            case XKB_KEY_XF86AudioStop:
+            case XKB_KEY_XF86AudioPrev:
+            case XKB_KEY_XF86AudioNext:
+            case XKB_KEY_XF86AudioMute:
+            case XKB_KEY_XF86AudioLowerVolume:
+            case XKB_KEY_XF86AudioRaiseVolume:
+                xcb_send_event(conn, true, screen->root, XCB_EVENT_MASK_BUTTON_PRESS, (char *)event);
+                return;
+        }
+    }
+
     switch (ksym) {
         case XKB_KEY_j:
         case XKB_KEY_m:
@@ -835,6 +852,7 @@ int main(int argc, char *argv[]) {
         {"ignore-empty-password", no_argument, NULL, 'e'},
         {"inactivity-timeout", required_argument, NULL, 'I'},
         {"show-failed-attempts", no_argument, NULL, 'f'},
+        {"pass-media-keys", no_argument, NULL, 'm'},
         {NULL, no_argument, NULL, 0}};
 
     if ((pw = getpwuid(getuid())) == NULL)
@@ -842,7 +860,7 @@ int main(int argc, char *argv[]) {
     if ((username = pw->pw_name) == NULL)
         errx(EXIT_FAILURE, "pw->pw_name is NULL.\n");
 
-    char *optstring = "hvnbdc:p:ui:teI:f";
+    char *optstring = "hvnbdc:p:ui:teI:fm";
     while ((o = getopt_long(argc, argv, optstring, longopts, &longoptind)) != -1) {
         switch (o) {
             case 'v':
@@ -900,9 +918,12 @@ int main(int argc, char *argv[]) {
             case 'f':
                 show_failed_attempts = true;
                 break;
+            case 'm':
+                pass_media_keys = true;
+                break;
             default:
                 errx(EXIT_FAILURE, "Syntax: i3lock [-v] [-n] [-b] [-d] [-c color] [-u] [-p win|default]"
-                                   " [-i image.png] [-t] [-e] [-I timeout] [-f]");
+                                   " [-i image.png] [-t] [-e] [-I timeout] [-f] [-m]");
         }
     }