diff --git a/mysys/my_thr_init.c b/mysys/my_thr_init.c
index db0881c3e37..123060302b4 100644
--- a/mysys/my_thr_init.c
+++ b/mysys/my_thr_init.c
@@ -354,7 +354,14 @@ void my_thread_end()
       tmp->dbug= NULL;
     }
     free(tmp);
-
+    /*
+     set_mysys_thread_var (NULL) must be called before signaling conditional variable
+     THR_COND_threads. This is variable on which my_thread_global_end is waiting.
+     After it is signalled THR_KEY_mysys_initialized is set to FALSE in my_thread_global_end.
+     There is a debug assertion that THE_KEY_mysys_initialized == TRUE in
+     set_my_sys_thread_var.
+    */
+    set_mysys_thread_var(NULL);
     /*
       Decrement counter for number of running threads. We are using this
       in my_thread_global_end() to wait until all threads have called
@@ -367,7 +374,6 @@ void my_thread_end()
       mysql_cond_signal(&THR_COND_threads);
     mysql_mutex_unlock(&THR_LOCK_threads);
   }
-  set_mysys_thread_var(NULL);
 #endif
 }
 
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index c70468b61be..aa43cfbde09 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -4490,6 +4490,8 @@ int mysqld_main(int argc, char **argv)
   sys_var_init();
   ulong requested_open_files;
   adjust_related_options(&requested_open_files);
+  // moved signal initialization here so that PFS thread inherited signal mask
+  my_init_signals();
 
 #ifdef WITH_PERFSCHEMA_STORAGE_ENGINE
   if (ho_error == 0)
@@ -4593,8 +4595,6 @@ int mysqld_main(int argc, char **argv)
   if (init_common_variables())
     unireg_abort(MYSQLD_ABORT_EXIT);        // Will do exit
 
-  my_init_signals();
-
   size_t guardize= 0;
 #ifndef _WIN32
   int retval= pthread_attr_getguardsize(&connection_attrib, &guardize);