diff --git a/d2renderers/d2fonts/d2fonts.go b/d2renderers/d2fonts/d2fonts.go
index 38b5cd3d9..85bd8b7f0 100644
--- a/d2renderers/d2fonts/d2fonts.go
+++ b/d2renderers/d2fonts/d2fonts.go
@@ -44,8 +44,13 @@ func (f Font) GetEncodedSubset(corpus string) string {
 
 	FontFamiliesMu.Lock()
 	defer FontFamiliesMu.Unlock()
-	fontBuf := make([]byte, len(FontFaces[f]))
-	copy(fontBuf, FontFaces[f])
+	var face []byte
+	{
+		ff, _ := FontFaces.Load(f)
+		face = ff.([]byte)
+	}
+	fontBuf := make([]byte, len(face))
+	copy(fontBuf, face)
 	fontBuf = font.UTF8CutFont(fontBuf, uniqueChars)
 
 	fontBuf, err := fontlib.Sfnt2Woff(fontBuf)
@@ -138,8 +143,8 @@ var fontFacesFS embed.FS
 // FontEncodings map[Font]string
 var FontEncodings sync.Map
 
-// TODO FontFaces map[Font][]byte
-var FontFaces map[Font][]byte
+// FontFaces map[Font][]byte
+var FontFaces sync.Map
 
 func init() {
 	FontEncodings.Store(
@@ -228,104 +233,103 @@ func init() {
 		return true
 	})
 
-	FontFaces = map[Font][]byte{}
 	b, err := fontFacesFS.ReadFile("ttf/SourceSansPro-Regular.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: SourceSansPro,
 		Style:  FONT_STYLE_REGULAR,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/SourceCodePro-Regular.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: SourceCodePro,
 		Style:  FONT_STYLE_REGULAR,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/SourceCodePro-Bold.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: SourceCodePro,
 		Style:  FONT_STYLE_BOLD,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/SourceCodePro-Semibold.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: SourceCodePro,
 		Style:  FONT_STYLE_SEMIBOLD,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/SourceCodePro-Italic.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: SourceCodePro,
 		Style:  FONT_STYLE_ITALIC,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/SourceSansPro-Bold.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: SourceSansPro,
 		Style:  FONT_STYLE_BOLD,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/SourceSansPro-Semibold.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: SourceSansPro,
 		Style:  FONT_STYLE_SEMIBOLD,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/SourceSansPro-Italic.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: SourceSansPro,
 		Style:  FONT_STYLE_ITALIC,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/FuzzyBubbles-Regular.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: HandDrawn,
 		Style:  FONT_STYLE_REGULAR,
-	}] = b
-	FontFaces[Font{
+	}, b)
+	FontFaces.Store(Font{
 		Family: HandDrawn,
 		Style:  FONT_STYLE_ITALIC,
-	}] = b
+	}, b)
 
 	b, err = fontFacesFS.ReadFile("ttf/FuzzyBubbles-Bold.ttf")
 	if err != nil {
 		panic(err)
 	}
-	FontFaces[Font{
+	FontFaces.Store(Font{
 		Family: HandDrawn,
 		Style:  FONT_STYLE_BOLD,
-	}] = b
-	FontFaces[Font{
+	}, b)
+	FontFaces.Store(Font{
 		Family: HandDrawn,
 		Style:  FONT_STYLE_SEMIBOLD,
-	}] = b
+	}, b)
 }
 
 var D2_FONT_TO_FAMILY = map[string]FontFamily{
@@ -334,7 +338,7 @@ var D2_FONT_TO_FAMILY = map[string]FontFamily{
 }
 
 func AddFontStyle(font Font, style FontStyle, ttf []byte) error {
-	FontFaces[font] = ttf
+	FontFaces.Store(font, ttf)
 
 	woff, err := fontlib.Sfnt2Woff(ttf)
 	if err != nil {
@@ -365,9 +369,10 @@ func AddFontFamily(name string, regularTTF, italicTTF, boldTTF, semiboldTTF []by
 			Family: SourceSansPro,
 			Style:  FONT_STYLE_REGULAR,
 		}
-		FontFaces[regularFont] = FontFaces[fallbackFont]
-		fb, _ := FontEncodings.Load(fallbackFont)
-		FontEncodings.Store(regularFont, fb)
+		f, _ := FontFaces.Load(fallbackFont)
+		FontFaces.Store(regularFont, f)
+		e, _ := FontEncodings.Load(fallbackFont)
+		FontEncodings.Store(regularFont, e)
 	}
 
 	italicFont := Font{
@@ -384,7 +389,8 @@ func AddFontFamily(name string, regularTTF, italicTTF, boldTTF, semiboldTTF []by
 			Family: SourceSansPro,
 			Style:  FONT_STYLE_ITALIC,
 		}
-		FontFaces[italicFont] = FontFaces[fallbackFont]
+		f, _ := FontFaces.Load(fallbackFont)
+		FontFaces.Store(italicFont, f)
 		fb, _ := FontEncodings.Load(fallbackFont)
 		FontEncodings.Store(italicFont, fb)
 	}
@@ -403,7 +409,8 @@ func AddFontFamily(name string, regularTTF, italicTTF, boldTTF, semiboldTTF []by
 			Family: SourceSansPro,
 			Style:  FONT_STYLE_BOLD,
 		}
-		FontFaces[boldFont] = FontFaces[fallbackFont]
+		f, _ := FontFaces.Load(fallbackFont)
+		FontFaces.Store(boldFont, f)
 		fb, _ := FontEncodings.Load(fallbackFont)
 		FontEncodings.Store(boldFont, fb)
 	}
@@ -422,7 +429,8 @@ func AddFontFamily(name string, regularTTF, italicTTF, boldTTF, semiboldTTF []by
 			Family: SourceSansPro,
 			Style:  FONT_STYLE_SEMIBOLD,
 		}
-		FontFaces[semiboldFont] = FontFaces[fallbackFont]
+		f, _ := FontFaces.Load(fallbackFont)
+		FontFaces.Store(semiboldFont, f)
 		fb, _ := FontEncodings.Load(fallbackFont)
 		FontEncodings.Store(semiboldFont, fb)
 	}
diff --git a/d2renderers/d2fonts/d2fonts_test.go b/d2renderers/d2fonts/d2fonts_test.go
index fc95ff310..1fd773241 100644
--- a/d2renderers/d2fonts/d2fonts_test.go
+++ b/d2renderers/d2fonts/d2fonts_test.go
@@ -14,8 +14,13 @@ func TestCutFont(t *testing.T) {
 		Family: SourceCodePro,
 		Style:  FONT_STYLE_BOLD,
 	}
-	fontBuf := make([]byte, len(FontFaces[f]))
-	copy(fontBuf, FontFaces[f])
+	var face []byte
+	{
+		ff, _ := FontFaces.Load(f)
+		face = ff.([]byte)
+	}
+	fontBuf := make([]byte, len(face))
+	copy(fontBuf, face)
 	fontBuf = font.UTF8CutFont(fontBuf, " 1")
 	err := diff.Testdata(filepath.Join("testdata", "d2fonts", "cut"), ".txt", fontBuf)
 	assert.Success(t, err)
diff --git a/lib/pdf/pdf.go b/lib/pdf/pdf.go
index 9d9eabe69..b1471f70a 100644
--- a/lib/pdf/pdf.go
+++ b/lib/pdf/pdf.go
@@ -31,8 +31,10 @@ func Init() *GoFPDF {
 		UnitStr: "pt",
 	})
 
-	newGofPDF.AddUTF8FontFromBytes("source", "", d2fonts.FontFaces[d2fonts.SourceSansPro.Font(0, d2fonts.FONT_STYLE_REGULAR)])
-	newGofPDF.AddUTF8FontFromBytes("source", "B", d2fonts.FontFaces[d2fonts.SourceSansPro.Font(0, d2fonts.FONT_STYLE_BOLD)])
+	reg, _ := d2fonts.FontFaces.Load(d2fonts.SourceSansPro.Font(0, d2fonts.FONT_STYLE_REGULAR))
+	bold, _ := d2fonts.FontFaces.Load(d2fonts.SourceSansPro.Font(0, d2fonts.FONT_STYLE_BOLD))
+	newGofPDF.AddUTF8FontFromBytes("source", "", reg.([]byte))
+	newGofPDF.AddUTF8FontFromBytes("source", "B", bold.([]byte))
 	newGofPDF.SetAutoPageBreak(false, 0)
 	newGofPDF.SetLineWidth(2)
 	newGofPDF.SetMargins(0, 0, 0)
diff --git a/lib/textmeasure/textmeasure.go b/lib/textmeasure/textmeasure.go
index 8df3a346e..004b48a3d 100644
--- a/lib/textmeasure/textmeasure.go
+++ b/lib/textmeasure/textmeasure.go
@@ -126,11 +126,12 @@ func NewRuler() (*Ruler, error) {
 				Style:  fontStyle,
 			}
 			// Note: FontFaces lookup is size-agnostic
-			if _, ok := d2fonts.FontFaces[font]; !ok {
+			face, has := d2fonts.FontFaces.Load(font)
+			if !has {
 				continue
 			}
 			if _, loaded := r.ttfs[font]; !loaded {
-				ttf, err := truetype.Parse(d2fonts.FontFaces[font])
+				ttf, err := truetype.Parse(face.([]byte))
 				if err != nil {
 					return nil, err
 				}