diff --git a/api/client.go b/api/client.go
index 93d68db182..f7c5c61fd5 100644
--- a/api/client.go
+++ b/api/client.go
@@ -50,7 +50,8 @@ const EnvVaultInsecure = "VAULT_SKIP_VERIFY"
 // returns an optional string duration to be used for response wrapping (e.g.
 // "15s", or simply "15"). The path will not begin with "/v1/" or "v1/" or "/",
 // however, end-of-path forward slashes are not trimmed, so must match your
-// called path precisely.
+// called path precisely. Response wrapping will only be used when the return
+// value is not the empty string.
 type WrappingLookupFunc func(operation, path string) string
 
 // Config is used to configure the creation of the client.
@@ -547,7 +548,7 @@ func (c *Client) SetOutputCurlString(curl bool) {
 }
 
 // CurrentWrappingLookupFunc sets a lookup function that returns desired wrap TTLs
-// for a given operation and path
+// for a given operation and path.
 func (c *Client) CurrentWrappingLookupFunc() WrappingLookupFunc {
 	c.modifyLock.RLock()
 	defer c.modifyLock.RUnlock()
@@ -556,7 +557,7 @@ func (c *Client) CurrentWrappingLookupFunc() WrappingLookupFunc {
 }
 
 // SetWrappingLookupFunc sets a lookup function that returns desired wrap TTLs
-// for a given operation and path
+// for a given operation and path.
 func (c *Client) SetWrappingLookupFunc(lookupFunc WrappingLookupFunc) {
 	c.modifyLock.Lock()
 	defer c.modifyLock.Unlock()
diff --git a/api/logical.go b/api/logical.go
index f4eb02a8df..977a41ae33 100644
--- a/api/logical.go
+++ b/api/logical.go
@@ -21,8 +21,9 @@ var (
 	// changed
 	DefaultWrappingTTL = "5m"
 
-	// The default function used if no other function is set, which honors the
-	// env var and wraps `sys/wrapping/wrap`
+	// The default function used if no other function is set. It honors the env
+	// var to set the wrap TTL. The default wrap TTL will apply when when writing
+	// to `sys/wrapping/wrap` when the env var is not set.
 	DefaultWrappingLookupFunc = func(operation, path string) string {
 		if os.Getenv(EnvVaultWrapTTL) != "" {
 			return os.Getenv(EnvVaultWrapTTL)