diff --git a/private/apigen/gogen.go b/private/apigen/gogen.go
index 2743ce01b..ed272ccdf 100644
--- a/private/apigen/gogen.go
+++ b/private/apigen/gogen.go
@@ -22,6 +22,7 @@ import (
 const DateFormat = "2006-01-02T15:04:05.999Z"
 
 // MustWriteGo writes generated Go code into a file.
+// If an error occurs, it panics.
 func (a *API) MustWriteGo(path string) {
 	generated, err := a.generateGo()
 	if err != nil {
diff --git a/private/apigen/tsgen.go b/private/apigen/tsgen.go
index c7b156975..1a7d86f65 100644
--- a/private/apigen/tsgen.go
+++ b/private/apigen/tsgen.go
@@ -13,6 +13,7 @@ import (
 )
 
 // MustWriteTS writes generated TypeScript code into a file.
+// If an error occurs, it panics.
 func (a *API) MustWriteTS(path string) {
 	f := newTSGenFile(path, a)