diff --git a/src/core/ngx_conf_file.c b/src/core/ngx_conf_file.c
index fb68800..b6c94a5 100644
--- a/src/core/ngx_conf_file.c
+++ b/src/core/ngx_conf_file.c
@@ -482,9 +482,22 @@
             if (len == ngx_pagesize) {
                 cf->conf_file->line = start_line;
 
+                if (d_quoted) {
+                    ch = '"';
+
+                } else if (s_quoted) {
+                    ch = '\'';
+
+                } else {
+                    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                                       "too long parameter \"%*s...\" started",
+                                       10, start);
+                    return NGX_ERROR;
+                }
+
                 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                                   "too long parameter \"%*s...\" started",
-                                   10, start);
+                                   "too long parameter, probably "
+                                   "missing terminating \"%c\" character", ch);
                 return NGX_ERROR;
             }