diff --git a/app/appearance/themes/daylight/theme.css b/app/appearance/themes/daylight/theme.css
index 86dc7cb66e6..f319975203b 100644
--- a/app/appearance/themes/daylight/theme.css
+++ b/app/appearance/themes/daylight/theme.css
@@ -26,7 +26,7 @@
     --b3-font-family: "Helvetica Neue", "Luxi Sans", "DejaVu Sans", "Hiragino Sans GB", "Segoe UI", "Microsoft Yahei", sans-serif, "Apple Color Emoji", "Noto Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Android Emoji", "EmojiSymbols";
     --b3-font-family-protyle: var(--b3-font-family);
     --b3-font-family-code: "JetBrainsMono-Regular", mononoki, Consolas, "Liberation Mono", Menlo, Courier, monospace, var(--b3-font-family);
-    --b3-font-family-graph: mononoki;
+    --b3-font-family-graph: arial;
     --b3-font-family-emoji: "Segoe UI Emoji", "Segoe UI Symbol", "Segoe UI", "Apple Color Emoji", "Twemoji Mozilla", "Noto Color Emoji", "Android Emoji";
     --b3-font-family-math: KaTeX_Math;
     --b3-font-size: 14px;
diff --git a/app/appearance/themes/midnight/theme.css b/app/appearance/themes/midnight/theme.css
index fbae409e936..bac4d5a230b 100644
--- a/app/appearance/themes/midnight/theme.css
+++ b/app/appearance/themes/midnight/theme.css
@@ -25,7 +25,7 @@
     --b3-font-family: "Helvetica Neue", "Luxi Sans", "DejaVu Sans", "Hiragino Sans GB", "Segoe UI", "Microsoft Yahei", sans-serif, "Apple Color Emoji", "Noto Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Android Emoji", "EmojiSymbols";
     --b3-font-family-protyle: var(--b3-font-family);
     --b3-font-family-code: "JetBrainsMono-Regular", mononoki, Consolas, "Liberation Mono", Menlo, Courier, monospace, var(--b3-font-family);
-    --b3-font-family-graph: mononoki;
+    --b3-font-family-graph: arial;
     --b3-font-family-emoji: "Segoe UI Emoji", "Segoe UI Symbol", "Segoe UI", "Apple Color Emoji", "Twemoji Mozilla", "Noto Color Emoji", "Android Emoji";
     --b3-font-family-math: KaTeX_Math;
     --b3-font-size: 14px;