diff --git a/third_party/txt/src/txt/font_collection.cc b/third_party/txt/src/txt/font_collection.cc
index 03e960a8d6dda8a11d14ed755092b8303831ce54..5503e54e03ff2516749c9f3356d834d029a302f0 100644
--- a/third_party/txt/src/txt/font_collection.cc
+++ b/third_party/txt/src/txt/font_collection.cc
@@ -132,8 +132,12 @@ FontCollection::GetMinikinFontCollectionForFamily(
         minikin_family,
     };
     if (enable_font_fallback_) {
-      for (std::string fallback_family : fallback_fonts_for_locale_[locale])
-        minikin_families.push_back(fallback_fonts_[fallback_family]);
+      for (std::string fallback_family : fallback_fonts_for_locale_[locale]) {
+        auto it = fallback_fonts_.find(fallback_family);
+        if (it != fallback_fonts_.end()) {
+          minikin_families.push_back(it->second);
+        }
+      }
     }
 
     // Create the minikin font collection.