diff --git a/src/core/evaluator.js b/src/core/evaluator.js
index 9bc1e75efe5f6..cff8b9f3304db 100644
--- a/src/core/evaluator.js
+++ b/src/core/evaluator.js
@@ -723,16 +723,25 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
           return errorFont();
         }
       }
+      let fallbackFont = false;
       if (!fontRef) {
         warn('fontRef not available');
-        return errorFont();
+        // Fallback to some default font. It will fallback to Helvetica.
+        this.handler.send('UnsupportedFeature',
+                          { featureId: UNSUPPORTED_FEATURES.font, });
+        fallbackFont = new Dict(xref);
+        fallbackFont._map.Subtype = new Name('Type1');
+        fallbackFont._map.BaseFont = new Name('PDFJS-FallbackFont');
       }
 
-      if (this.fontCache.has(fontRef)) {
+      if (fontRef && this.fontCache.has(fontRef)) {
         return this.fontCache.get(fontRef);
       }
 
       font = xref.fetchIfRef(fontRef);
+      if (fallbackFont) {
+        font = fallbackFont;
+      }
       if (!isDict(font)) {
         return errorFont();
       }