diff --git a/assets/ci/octave_ci.m b/assets/ci/octave_ci.m
index 88b492b..1685f04 100644
--- a/assets/ci/octave_ci.m
+++ b/assets/ci/octave_ci.m
@@ -191,11 +191,18 @@ function pkg_install_sha256_check (pkg_version, test_dir)
   urlwrite (pkg_version.url, pkg_file);
   sha256_sum = hash ("sha256", fileread (pkg_file));
   if (! strcmp (sha256_sum, pkg_version.sha256))
-    step_error (sprintf (["Package checksum error:\n", ...
-      "\n\tFile: %s", ...
-      "\n\tExpected: '%s'", ...
-      "\n\tBut got:  '%s'\n"], pkg_file, pkg_version.sha256, sha256_sum));
-    exit (1);  # Return test failed.
+    if (isempty (sha256_sum))
+      step_warning (sprintf (["No package checksum:\n", ...
+        "\n\tFile: %s", ...
+        "\n\tExpected: '%s'", ...
+        "\n\tBut sha256 was empty.\n"], pkg_file, pkg_version.sha256));
+    else
+      step_error (sprintf (["Package checksum error:\n", ...
+        "\n\tFile: %s", ...
+        "\n\tExpected: '%s'", ...
+        "\n\tBut got:  '%s'\n"], pkg_file, pkg_version.sha256, sha256_sum));
+      exit (1);  # Return test failed.
+    endif
   else
     disp (["sha256 checksum ok: '", sha256_sum, "'"]);
   endif