diff --git a/pkg/invoices.go b/pkg/invoices.go
index 6618df6..da67717 100644
--- a/pkg/invoices.go
+++ b/pkg/invoices.go
@@ -275,7 +275,7 @@ func ServeInvoice(w http.ResponseWriter, r *http.Request, params httprouter.Para
 }
 
 func mustWriteInvoicePdf(w io.Writer, r *http.Request, inv *invoice) {
-	cmd := exec.Command("weasyprint", "--format", "pdf", "--stylesheet", "web/static/invoice.css", "-", "-")
+	cmd := exec.Command("weasyprint", "--stylesheet", "web/static/invoice.css", "-", "-")
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr
 	stdin, err := cmd.StdinPipe()
diff --git a/pkg/quote.go b/pkg/quote.go
index bb9c758..fa277d0 100644
--- a/pkg/quote.go
+++ b/pkg/quote.go
@@ -272,7 +272,7 @@ func ServeQuote(w http.ResponseWriter, r *http.Request, params httprouter.Params
 }
 
 func mustWriteQuotePdf(w io.Writer, r *http.Request, quo *quote) {
-	cmd := exec.Command("weasyprint", "--format", "pdf", "--stylesheet", "web/static/invoice.css", "-", "-")
+	cmd := exec.Command("weasyprint", "--stylesheet", "web/static/invoice.css", "-", "-")
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr
 	stdin, err := cmd.StdinPipe()