--- a/auto/options
+++ b/auto/options
@@ -391,8 +391,7 @@
         --test-build-solaris-sendfilev)  NGX_TEST_BUILD_SOLARIS_SENDFILEV=YES ;;
 
         *)
-            echo "$0: error: invalid option \"$option\""
-            exit 1
+            echo "$0: error: ignoring invalid option \"$option\""
         ;;
     esac
 done