diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index 49d6c3a..6f1de59 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -204,12 +204,10 @@
 
     call assert_equal('inf', printf('%f', 1.0/0.0))
 
-    " This prints inf but shouldn't it print -inf instead?
-    call assert_match('^-\?inf$', printf('%f', -1.0/0.0))
+    call assert_match('^-inf$', printf('%f', -1.0/0.0))
 
-    " This prints -nan but shouldn't it print nan instead?
-    call assert_match('^-\?nan$', printf('%f', sqrt(-1.0)))
-    call assert_match('^-\?nan$', printf('%f', 0.0/0.0))
+    call assert_match('^nan$', printf('%f', sqrt(-1.0)))
+    call assert_match('^nan$', printf('%f', 0.0/0.0))
 
     call assert_fails('echo printf("%f", "a")', 'E807:')
   endif