diff --git a/builtin/providers/vsphere/provider.go b/builtin/providers/vsphere/provider.go
index c13f089b2..be46b50d6 100644
--- a/builtin/providers/vsphere/provider.go
+++ b/builtin/providers/vsphere/provider.go
@@ -52,13 +52,13 @@ func Provider() terraform.ResourceProvider {
 			"client_debug_path_run": &schema.Schema{
 				Type:        schema.TypeString,
 				Optional:    true,
-				DefaultFunc: schema.EnvDefaultFunc("VSPHERE_CLIENT_DEBUG_PATH_RUN", nil),
+				DefaultFunc: schema.EnvDefaultFunc("VSPHERE_CLIENT_DEBUG_PATH_RUN", ""),
 				Description: "govomomi debug path for a single run",
 			},
 			"client_debug_path": &schema.Schema{
 				Type:        schema.TypeString,
 				Optional:    true,
-				DefaultFunc: schema.EnvDefaultFunc("VSPHERE_CLIENT_DEBUG_PATH", nil),
+				DefaultFunc: schema.EnvDefaultFunc("VSPHERE_CLIENT_DEBUG_PATH", ""),
 				Description: "govomomi debug path for debug",
 			},
 		},