diff --git a/src/testdir/test_channel.vim b/src/testdir/test_channel.vim
index 8fcc73b..e5903ae 100644
--- a/src/testdir/test_channel.vim
+++ b/src/testdir/test_channel.vim
@@ -187,7 +187,7 @@
     call ch_close(handle)
   else
     let elapsed = reltime(start)
-    call assert_true(elapsed < 1.0)
+    call assert_true(reltimefloat(elapsed) < 1.0)
   endif
 
   let start = reltime()
@@ -198,6 +198,6 @@
   else
     " Failed connection doesn't wait the full time.
     let elapsed = reltime(start)
-    call assert_true(elapsed < 1.0)
+    call assert_true(reltimefloat(elapsed) < 1.0)
   endif
 endfunc