diff --git a/src/text/template/parse/parse.go b/src/text/template/parse/parse.go
index 5e6e512eb4..ff1358b001 100644
--- a/src/text/template/parse/parse.go
+++ b/src/text/template/parse/parse.go
@@ -38,7 +38,8 @@ type Tree struct {
 type Mode uint
 
 const (
-	ParseComments Mode = 1 << iota // parse comments and add them to AST
+	ParseComments  Mode = 1 << iota // parse comments and add them to AST
+	DeferFuncCheck                  // defer type checking functions until template is executed
 )
 
 // Copy returns a copy of the Tree. Any parsing state is discarded.
@@ -689,7 +690,8 @@ func (t *Tree) operand() Node {
 func (t *Tree) term() Node {
 	switch token := t.nextNonSpace(); token.typ {
 	case itemIdentifier:
-		if !t.hasFunction(token.val) {
+		checkFunc := t.Mode&DeferFuncCheck == 0
+		if checkFunc && !t.hasFunction(token.val) {
 			t.errorf("function %q not defined", token.val)
 		}
 		return NewIdentifier(token.val).SetTree(t).SetPos(token.pos)
diff --git a/src/text/template/parse/parse_test.go b/src/text/template/parse/parse_test.go
index 220f984777..c4585f6912 100644
--- a/src/text/template/parse/parse_test.go
+++ b/src/text/template/parse/parse_test.go
@@ -379,6 +379,22 @@ func TestParseWithComments(t *testing.T) {
 	}
 }
 
+func TestDeferFuncCheck(t *testing.T) {
+	oldTextFormat := textFormat
+	textFormat = "%q"
+	defer func() { textFormat = oldTextFormat }()
+	tr := New("defer func check")
+	tr.Mode = DeferFuncCheck
+	tmpl, err := tr.Parse("{{fn 1 2}}", "", "", make(map[string]*Tree))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	expected := "{{fn 1 2}}"
+	if result := tmpl.Root.String(); result != expected {
+		t.Errorf("got\n\t%v\nexpected\n\t%v", result, expected)
+	}
+}
+
 type isEmptyTest struct {
 	name  string
 	input string