--- a/liboctave/CmplxQRP.cc
+++ b/liboctave/CmplxQRP.cc
@@ -77,7 +77,8 @@
                                  tau, &clwork, -1, rwork, info));
 
       // allocate buffer and do the job.
-      octave_idx_type lwork = clwork.real (); lwork = std::max (lwork, 1);
+      octave_idx_type lwork = clwork.real ();
+      lwork = std::max (lwork, static_cast<octave_idx_type> (1));
       OCTAVE_LOCAL_BUFFER (Complex, work, lwork);
       F77_XFCN (zgeqp3, ZGEQP3, (m, n, afact.fortran_vec (), m, jpvt.fortran_vec (),
                                  tau, work, lwork, rwork, info));
@@ -88,7 +89,7 @@
   // Form Permutation matrix (if economy is requested, return the
   // indices only!)
 
-  jpvt -= 1;
+  jpvt -= static_cast<octave_idx_type> (1);
   p = PermMatrix (jpvt, true);