diff --git a/NEWS b/NEWS
index 6a56544a46c..ee902be48e4 100644
--- a/NEWS
+++ b/NEWS
@@ -17,6 +17,8 @@ PHP                                                                        NEWS
   . Fixed bug #68207 (Setting fastcgi.error_header can result in a WARNING).
     (Jakub Zelenka)
   . Fixed bug #80669 (FPM numeric user fails to set groups). (Jakub Zelenka)
+  . Fixed bug GH-8517 (Random crash of FPM master process in
+    fpm_stdio_child_said). (Jakub Zelenka)
 
 - MBString:
   . Fixed bug GH-9535 (The behavior of mb_strcut in mbstring has been changed in
diff --git a/sapi/fpm/fpm/fpm_children.c b/sapi/fpm/fpm/fpm_children.c
index 741fc276315..6a5787c7ec8 100644
--- a/sapi/fpm/fpm/fpm_children.c
+++ b/sapi/fpm/fpm/fpm_children.c
@@ -120,7 +120,7 @@ static void fpm_child_unlink(struct fpm_child_s *child) /* {{{ */
 }
 /* }}} */
 
-static struct fpm_child_s *fpm_child_find(pid_t pid) /* {{{ */
+struct fpm_child_s *fpm_child_find(pid_t pid) /* {{{ */
 {
 	struct fpm_worker_pool_s *wp;
 	struct fpm_child_s *child = 0;
diff --git a/sapi/fpm/fpm/fpm_children.h b/sapi/fpm/fpm/fpm_children.h
index 5ae4e2062e4..679c34ba038 100644
--- a/sapi/fpm/fpm/fpm_children.h
+++ b/sapi/fpm/fpm/fpm_children.h
@@ -10,13 +10,14 @@
 #include "fpm_events.h"
 #include "zlog.h"
 
+struct fpm_child_s;
+
 int fpm_children_create_initial(struct fpm_worker_pool_s *wp);
 int fpm_children_free(struct fpm_child_s *child);
 void fpm_children_bury(void);
 int fpm_children_init_main(void);
 int fpm_children_make(struct fpm_worker_pool_s *wp, int in_event_loop, int nb_to_spawn, int is_debug);
-
-struct fpm_child_s;
+struct fpm_child_s *fpm_child_find(pid_t pid);
 
 struct fpm_child_s {
 	struct fpm_child_s *prev, *next;
diff --git a/sapi/fpm/fpm/fpm_stdio.c b/sapi/fpm/fpm/fpm_stdio.c
index 1dc65aaa345..46cf4aaa285 100644
--- a/sapi/fpm/fpm/fpm_stdio.c
+++ b/sapi/fpm/fpm/fpm_stdio.c
@@ -181,7 +181,10 @@ static void fpm_stdio_child_said(struct fpm_event_s *ev, short which, void *arg)
 	if (!arg) {
 		return;
 	}
-	child = (struct fpm_child_s *)arg;
+	child = fpm_child_find((intptr_t) arg);
+	if (!child) {
+		return;
+	}
 
 	is_stdout = (fd == child->fd_stdout);
 	if (is_stdout) {
@@ -327,10 +330,10 @@ int fpm_stdio_parent_use_pipes(struct fpm_child_s *child) /* {{{ */
 	child->fd_stdout = fd_stdout[0];
 	child->fd_stderr = fd_stderr[0];
 
-	fpm_event_set(&child->ev_stdout, child->fd_stdout, FPM_EV_READ, fpm_stdio_child_said, child);
+	fpm_event_set(&child->ev_stdout, child->fd_stdout, FPM_EV_READ, fpm_stdio_child_said, (void *) (intptr_t) child->pid);
 	fpm_event_add(&child->ev_stdout, 0);
 
-	fpm_event_set(&child->ev_stderr, child->fd_stderr, FPM_EV_READ, fpm_stdio_child_said, child);
+	fpm_event_set(&child->ev_stderr, child->fd_stderr, FPM_EV_READ, fpm_stdio_child_said, (void *) (intptr_t) child->pid);
 	fpm_event_add(&child->ev_stderr, 0);
 	return 0;
 }