diff --git a/src/tool_parsecfg.c b/src/tool_parsecfg.c
index 4d5145bcc..71be83d71 100644
--- a/src/tool_parsecfg.c
+++ b/src/tool_parsecfg.c
@@ -188,6 +188,24 @@ int parseconfig(const char *filename,
         while(*line && !ISSPACE(*line))
           line++;
         *line = '\0'; /* zero terminate */
+
+        /* to detect mistakes better, see if there's data following */
+        line++;
+        /* pass all spaces */
+        while(*line && ISSPACE(*line))
+          line++;
+
+        switch(*line) {
+        case '\0':
+        case '\r':
+        case '\n':
+        case '#': /* comment */
+          break;
+        default:
+          warnf(config, "%s:%d: warning: '%s' uses unquoted white space in the"
+                " line that may cause side-effects!\n",
+                filename, lineno, option);
+        }
       }
 
       if(param && !*param) {