diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index 605102558..3ff0f75c6 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -291,6 +291,11 @@ ngx_single_process_cycle(ngx_cycle_t *cycle)
 {
     ngx_uint_t  i;
 
+    if (ngx_set_environment(cycle, NULL) == NULL) {
+        /* fatal */
+        exit(2);
+    }
+
     for (i = 0; ngx_modules[i]; i++) {
         if (ngx_modules[i]->init_process) {
             if (ngx_modules[i]->init_process(cycle) == NGX_ERROR) {