diff --git a/pynvim/plugin/script_host.py b/pynvim/plugin/script_host.py
index 36893176..1efb9457 100644
--- a/pynvim/plugin/script_host.py
+++ b/pynvim/plugin/script_host.py
@@ -194,7 +194,7 @@ def writelines(self, seq):
 
 
 def num_to_str(obj):
-    if isinstance(obj, num_types):
+    if isinstance(obj, num_types) and not isinstance(obj, bool):
         return str(obj)
     else:
         return obj
diff --git a/test/test_host.py b/test/test_host.py
index b21a398b..92de91fe 100644
--- a/test/test_host.py
+++ b/test/test_host.py
@@ -28,3 +28,10 @@ def test_host_async_error(vim):
     assert event[1] == 'nvim_error_event'
     assert 'rplugin-host: Async request caused an error:\nboom\n' \
            in h._on_error_event(None, 'boom')
+
+def test_legacy_vim_eval(vim):
+    h = ScriptHost(vim)
+    assert h.legacy_vim.eval('1') == '1'
+    assert h.legacy_vim.eval('v:null') == None
+    assert h.legacy_vim.eval('v:true') == True
+    assert h.legacy_vim.eval('v:false') == False