--- a/src/core/ngx_conf_file.c
+++ b/src/core/ngx_conf_file.c
@@ -959,31 +959,47 @@ void ngx_cdecl
 ngx_conf_log_error(ngx_uint_t level, ngx_conf_t *cf, ngx_err_t err,
     char *fmt, ...)
 {
-    u_char   errstr[NGX_MAX_CONF_ERRSTR], *buf, *last;
+    u_char   errstr[NGX_MAX_CONF_ERRSTR], *p, *last;
     va_list  args;
 
     last = errstr + NGX_MAX_CONF_ERRSTR;
 
     va_start(args, fmt);
-    buf = ngx_vsnprintf(errstr, last - errstr, fmt, args);
+    p = ngx_vsnprintf(errstr, last - errstr, fmt, args);
     va_end(args);
 
-    *buf = '\0';
+    if (err) {
+
+        if (p > last - 50) {
+
+            /* leave a space for an error code */
 
-    if (err) {
-        buf = ngx_snprintf(buf, last - buf - 1, " (%d: ", err);
-        buf = ngx_strerror_r(err, buf, last - buf - 1);
-        *buf++ = ')';
-        *buf = '\0';
+            p = last - 50;
+            *p++ = '.';
+            *p++ = '.';
+            *p++ = '.';
+        }
+
+#if (NGX_WIN32)
+        p = ngx_snprintf(p, last - p, ((unsigned) err < 0x80000000)
+                                           ? " (%d: " : " (%Xd: ", err);
+#else
+        p = ngx_snprintf(p, last - p, " (%d: ", err);
+#endif
+
+        p = ngx_strerror_r(err, p, last - p);
+
+        *p++ = ')';
     }
 
     if (cf->conf_file == NULL) {
-        ngx_log_error(level, cf->log, 0, "%s", errstr);
+        ngx_log_error(level, cf->log, 0, "%*s", p - errstr, errstr);
         return;
     }
 
-    ngx_log_error(level, cf->log, 0, "%s in %s:%ui",
-                  errstr, cf->conf_file->file.name.data, cf->conf_file->line);
+    ngx_log_error(level, cf->log, 0, "%*s in %s:%ui",
+                  p - errstr, errstr,
+                  cf->conf_file->file.name.data, cf->conf_file->line);
 }
 
 

--- a/src/core/ngx_conf_file.h
+++ b/src/core/ngx_conf_file.h
@@ -71,7 +71,7 @@
 #define NGX_CONF_MODULE      0x464E4F43  /* "CONF" */
 
 
-#define NGX_MAX_CONF_ERRSTR  256
+#define NGX_MAX_CONF_ERRSTR  1024
 
 
 struct ngx_command_s {