diff --git a/src/algs/slsqp/slsqp.c b/src/algs/slsqp/slsqp.c
index e6360624..2d9763eb 100644
--- a/src/algs/slsqp/slsqp.c
+++ b/src/algs/slsqp/slsqp.c
@@ -2459,7 +2459,7 @@ nlopt_result nlopt_slsqp(unsigned n, nlopt_func f, void *f_data,
      unsigned max_cdim;
      int want_grad = 1;
      
-     if (p > n) {
+     if (ptot > n) {
        nlopt_stop_msg(stop, "slsqp: more equality constraints than variables");
        return NLOPT_INVALID_ARGS;
      }