diff --git a/README.md b/README.md
index 244345c..20fc37a 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,11 @@ Apply [Go templates](https://golang.org/pkg/text/template/#hdr-Text_and_spaces)
 
     goproc <Go-template-file> <JSON-or-YAML-file>
 
-## Go template functions extensions
+## Template syntax
+
+See the [Go templates](https://golang.org/pkg/text/template/#hdr-Text_and_spaces) documentation.
+
+## Functions extensions
 
 The following functions are added in addition to the standard functions.
 
@@ -19,9 +23,10 @@ The following functions are added in addition to the standard functions.
 To ease the extraction of data, `jsonptr` allows to express data location using
 JSON Pointer ([RFC 6901](https://tools.ietf.org/html/rfc6901)).
 
-Usage:
+Usages:
 
-    {{ jsonptr . "pointer" }}
+    {{ jsonptr "pointer" . }}
+    {{ . | jsonptr "pointer" }}
 
 Examples:
 
diff --git a/main.go b/main.go
index df1a11b..5bf64e9 100644
--- a/main.go
+++ b/main.go
@@ -56,7 +56,9 @@ func _main() error {
 
 	tmpl := template.New("")
 	tmpl.Funcs(template.FuncMap{
-		"jsonptr": jsonptr.Get,
+		"jsonptr": func(ptr string, doc interface{}) (interface{}, error) {
+			return jsonptr.Get(doc, ptr)
+		},
 	})
 
 	var err error
diff --git a/testdata/02.gotmpl b/testdata/02.gotmpl
index 5fe8d2a..a3687d9 100644
--- a/testdata/02.gotmpl
+++ b/testdata/02.gotmpl
@@ -1,2 +1,2 @@
-Hello, {{ jsonptr . "" }}!
+Hello, {{ jsonptr "" . }}!
 {{/* vim: syntax=gotexttmpl: */ -}}
\ No newline at end of file
diff --git a/testdata/03.gotmpl b/testdata/03.gotmpl
index b394de3..1b327c4 100644
--- a/testdata/03.gotmpl
+++ b/testdata/03.gotmpl
@@ -1,2 +1,2 @@
-Hello, {{ jsonptr . "/name" }}!
+Hello, {{ . | jsonptr "/name" }}!
 {{/* vim: syntax=gotexttmpl: */ -}}
\ No newline at end of file