diff --git a/font.go b/font.go
index 7d4d880..6b8d940 100644
--- a/font.go
+++ b/font.go
@@ -34,6 +34,15 @@ func LoadFont(data []byte) (*Font, error) {
 	// The face is sized to the em, so AdvanceIndexUnits returns advances in font
 	// units — exactly what a PDF /W width array wants — at the base (uninstanced)
 	// design.
+	// opentype accepts a font with no character map; pdfkit cannot. Every text
+	// call resolves runes through Font.GlyphIndex, so a font without a 'cmap'
+	// maps nothing and would silently draw a page of blanks. The requirement is
+	// pdfkit's own and is stated here, rather than borrowed from however strict
+	// the parser happens to be.
+	if _, ok := ot.Table("cmap"); !ok {
+		return nil, fmt.Errorf("pdfkit: parse font: no cmap table, the font maps no characters")
+	}
+
 	face := ot.NewFace(ot.UnitsPerEm())
 
 	name := ""
diff --git a/font_test.go b/font_test.go
index a4fefa3..bcc9be3 100644
--- a/font_test.go
+++ b/font_test.go
@@ -10,8 +10,9 @@ func TestLoadFontErrors(t *testing.T) {
 	if _, err := LoadFont([]byte("not a font")); err == nil {
 		t.Error("expected opentype parse error")
 	}
-	// A valid sfnt container missing cmap: opentype (which requires a cmap)
-	// rejects it, covering LoadFont's error branch.
+	// A valid sfnt container missing cmap. opentype used to reject this and the
+	// test leaned on that; since it became optional upstream, LoadFont makes the
+	// check itself, because pdfkit resolves every rune through the cmap.
 	if _, err := LoadFont(synthTTF(synthOpts{noCmap: true})); err == nil {
 		t.Error("expected opentype parse error for missing cmap")
 	}
diff --git a/go.mod b/go.mod
index 2464cd2..0cdd7d1 100644
--- a/go.mod
+++ b/go.mod
@@ -2,11 +2,11 @@ module github.com/go-pdfkit/pdfkit
 
 go 1.26.4
 
-require github.com/go-opentype/opentype v0.6.0
+require github.com/go-opentype/opentype v0.12.0
 
 require (
-	github.com/go-widgets/painter v0.11.0
-	github.com/go-widgets/toolkit v0.288.0
+	github.com/go-widgets/painter v0.12.0
+	github.com/go-widgets/toolkit v0.289.0
 	rsc.io/pdf v0.1.1
 )
 
diff --git a/go.sum b/go.sum
index 63a93a2..1ba8029 100644
--- a/go.sum
+++ b/go.sum
@@ -20,8 +20,8 @@ github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
 github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
 github.com/go-opentype/fonts v0.8.0 h1:77i3VPIH90GbstzNb21mk+an4WvEOe2idC6W+J0n0fw=
 github.com/go-opentype/fonts v0.8.0/go.mod h1:C6yQL2apHItfEZ5hztpsHF0S5mlX/hklLlq/Z5fRG/g=
-github.com/go-opentype/opentype v0.6.0 h1:2t1Qs/Uo4M+f9gahV5QGihLTTeI/q4s0l7MIsbkd290=
-github.com/go-opentype/opentype v0.6.0/go.mod h1:AOixevJf7XQaH7+WG+OMIOZEbYPXfMqklVk26Y6YTUU=
+github.com/go-opentype/opentype v0.12.0 h1:wBlcDi+3ZaNZXEt5z+Ixr11/cYYwi5W+jX6yTl/qr1I=
+github.com/go-opentype/opentype v0.12.0/go.mod h1:AOixevJf7XQaH7+WG+OMIOZEbYPXfMqklVk26Y6YTUU=
 github.com/go-opentype/shape v0.5.0 h1:jHNaOMHNBdDj5EixOevlrrsi92svMxvVMKN7GYaPfxo=
 github.com/go-opentype/shape v0.5.0/go.mod h1:3ImRYNIj6zpwWQ/DV3BWhgMFfmzDITH6XpZw2auQHTo=
 github.com/go-richdoc/richdoc v0.2.0 h1:z9cLox9MoInZL6fIlweMzgDT/VqgnB2ZucSIEaRFglY=
@@ -30,10 +30,10 @@ github.com/go-typeset/bidi v0.3.0 h1:4fjGjejvjE2LzLNzY4si8PkVO321NcsKIiANhWT3jF4
 github.com/go-typeset/bidi v0.3.0/go.mod h1:ct3cmYT8Qt1FGJQ+2QaakrUxqaP4ZysgdQQg2ym5+Xo=
 github.com/go-widgets/mvvm v0.5.0 h1:o5hh6HAxbApONcbZxmyV9q12pCAPGRd6L24aS3gaCbA=
 github.com/go-widgets/mvvm v0.5.0/go.mod h1:Phdrd434RLxXW1D6dL1PPQH1tABwYLIN2X7jQVC4TbY=
-github.com/go-widgets/painter v0.11.0 h1:xsj4zTz8B43rOZnWrx7ZsaUBMgJyvgaE/Pq2FfcG2Sw=
-github.com/go-widgets/painter v0.11.0/go.mod h1:IPRLqdUJuJX8sfuHeYLZCzjoLvA0ApbOlyIAVmguJDQ=
-github.com/go-widgets/toolkit v0.288.0 h1:vtQDXZAbZRSQqIoEYQf/xE8ARE4YV4QtfHGHgnKP6NM=
-github.com/go-widgets/toolkit v0.288.0/go.mod h1:IaRQFcV6FjxwzGXpHd3dpEoWZ+82f7dMPwtEZSH4nIg=
+github.com/go-widgets/painter v0.12.0 h1:gMqTVbIbGSKmaE28NKsbbKdNIk2drupNMNuLjFP6T6I=
+github.com/go-widgets/painter v0.12.0/go.mod h1:IPRLqdUJuJX8sfuHeYLZCzjoLvA0ApbOlyIAVmguJDQ=
+github.com/go-widgets/toolkit v0.289.0 h1:iVbye2D7YMAkUOcJOXYNZKXqyeOmnxtRhdzEBlbBcz8=
+github.com/go-widgets/toolkit v0.289.0/go.mod h1:IaRQFcV6FjxwzGXpHd3dpEoWZ+82f7dMPwtEZSH4nIg=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=