diff --git a/src/core/ngx_module.c b/src/core/ngx_module.c
index 3e3c50683..bd36f1601 100644
--- a/src/core/ngx_module.c
+++ b/src/core/ngx_module.c
@@ -139,6 +139,10 @@ ngx_count_modules(ngx_cycle_t *cycle, ngx_uint_t type)
                 continue;
             }
 
+            if (module->ctx_index == NGX_MODULE_UNSET_INDEX) {
+                continue;
+            }
+
             if (module->ctx_index > max) {
                 max = module->ctx_index;
             }