--- a/auto/options
+++ b/auto/options
@@ -397,8 +397,7 @@ $0: warning: the \"--with-sha1-asm\" opt
         --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
