diff -ur arpack-ng-3.7.0_org/TESTS/bug_58_double.f arpack-ng-3.7.0/TESTS/bug_58_double.f
--- arpack-ng-3.7.0_org/TESTS/bug_58_double.f	2019-10-17 12:17:22.496987817 +0900
+++ arpack-ng-3.7.0/TESTS/bug_58_double.f	2019-10-17 17:12:37.669353870 +0900
@@ -69,7 +69,7 @@
      &                  workev(3*maxncv),
      &                  workl(3*maxncv*maxncv+6*maxncv),
      &                  dd(maxn), dl(maxn), du(maxn),
-     &                  du2(maxn), a(maxn,maxn), c(maxn,maxn)
+     &                  du2(maxn), a(maxn,maxn), c(maxn,maxn), rslt
 c
 c     %---------------%
 c     | Local Scalars |
@@ -417,7 +417,8 @@
          print *, ' '
 c
       end if
-      if (isnan(v(1,1))) then
+      rslt = v(1,1)
+      if (rslt .ne. rslt) then
          stop 1
       end if
 c