diff --git a/assets/css/app.css b/assets/css/app.css
index 342628f..aaeff2c 100644
--- a/assets/css/app.css
+++ b/assets/css/app.css
@@ -122,24 +122,24 @@ code.inline {
 
 @font-face {
     font-family: "iAWriterDuo";
-    src: url("/fonts/iAWriterDuoV.ttf");
+    src: url("/fonts/iAWriterDuoV.ttf") format('truetype');
     font-style: normal;
 }
 
 @font-face {
     font-family: "iAWriterDuo";
-    src: url("/fonts/iAWriterDuoV-Italic.ttf");
+    src: url("/fonts/iAWriterDuoV-Italic.ttf") format('truetype');
     font-style: italic;
 }
 
 @font-face {
     font-family: "iAWriterMono";
-    src: url("/fonts/iAWriterMonoV.ttf");
+    src: url("/fonts/iAWriterMonoV.ttf") format('truetype');
     font-style: normal;
 }
 
 @font-face {
     font-family: "iAWriterMono";
-    src: url("/fonts/iAWriterMonoV-Italic.ttf");
+    src: url("/fonts/iAWriterMonoV-Italic.ttf") format('truetype');
     font-style: italic;
 }