diff --git a/modules/dav/main/util.c b/modules/dav/main/util.c

index 1ae5914027c..3f7822fc931 100644

--- a/modules/dav/main/util.c

+++ b/modules/dav/main/util.c

@@ -801,8 +801,14 @@ static dav_error * dav_process_if_header(request_rec *r, dav_if_header **p_ih)

                                                  "for the same state.");

                         }

                         condition = DAV_IF_COND_NOT;

+                        list += 2;

+                    }

+                    else {

+                        return dav_new_error(r->pool, HTTP_BAD_REQUEST,

+                                             DAV_ERR_IF_UNK_CHAR, 0,

+                                             "Invalid \"If:\" header: "

+                                             "Unexpected character in List");

                     }

-                    list += 2;

                     break;

                 case ' ':