diff --git a/conf.d/40-nonlatin.conf b/conf.d/40-nonlatin.conf
index 0af8832..19cb103 100644
--- a/conf.d/40-nonlatin.conf
+++ b/conf.d/40-nonlatin.conf
@@ -233,4 +233,104 @@
 		<default><family>cursive</family></default>
 	</alias>
 
+<!--
+  system-ui
+-->
+	<alias>
+		<family>Noto Sans Arabic UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Bengali UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Devanagari UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Gujarati UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Gurmukhi UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Kannada UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Khmer UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Lao UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Malayalam UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Myanmar UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Oriya UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Sinhala UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Tamil UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Telugu UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans Thai UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Leelawadee UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Nirmala UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Yu Gothic UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Meiryo UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>MS UI Gothic</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Khmer UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Lao UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Microsoft JhengHei UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Microsoft YaHei UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+
 </fontconfig>
diff --git a/conf.d/45-latin.conf b/conf.d/45-latin.conf
index a9240b9..a33420e 100644
--- a/conf.d/45-latin.conf
+++ b/conf.d/45-latin.conf
@@ -274,5 +274,28 @@
 		<family>Zapfino</family>
 		<default><family>cursive</family></default>
 	</alias>
+<!--
+  system-ui
+-->
+	<alias>
+		<family>Cantarell</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Noto Sans UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Segoe UI</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Segoe UI Historic</family>
+		<default><family>system-ui</family></default>
+	</alias>
+	<alias>
+		<family>Segoe UI Symbol</family>
+		<default><family>system-ui</family></default>
+	</alias>
 
 </fontconfig>
diff --git a/conf.d/60-latin.conf b/conf.d/60-latin.conf
index 5be5d6a..8ba894e 100644
--- a/conf.d/60-latin.conf
+++ b/conf.d/60-latin.conf
@@ -75,5 +75,18 @@
 			<family>Comic Sans MS</family>
 		</prefer>
 	</alias>
+<!--
+  system-ui
+-->
+	<alias>
+		<family>system-ui</family>
+		<prefer>
+			<family>Cantarell</family>
+			<family>Noto Sans UI</family>
+			<family>Segoe UI</family>
+			<family>Segoe UI Historic</family>
+			<family>Segoe UI Symbol</family>
+		</prefer>
+	</alias>
 
 </fontconfig>
diff --git a/conf.d/65-nonlatin.conf b/conf.d/65-nonlatin.conf
index 1b9de31..33ff53e 100644
--- a/conf.d/65-nonlatin.conf
+++ b/conf.d/65-nonlatin.conf
@@ -196,4 +196,37 @@
 			<family>LKLUG</family>
 		</prefer>
 	</alias>
+<!--
+  system-ui
+-->
+	<alias>
+		<family>system-ui</family>
+		<prefer>
+			<family>Noto Sans Arabic UI</family><!-- ar -->
+			<family>Noto Sans Bengali UI</family><!-- bn -->
+			<family>Noto Sans Devanagari UI</family><!-- hi, mai, mr -->
+			<family>Noto Sans Gujarati UI</family><!-- gu -->
+			<family>Noto Sans Gurmukhi UI</family><!-- pa -->
+			<family>Noto Sans Kannada UI</family><!-- kn -->
+			<family>Noto Sans Khmer UI</family><!-- km -->
+			<family>Noto Sans Lao UI</family><!-- lo -->
+			<family>Noto Sans Malayalam UI</family><!-- ml -->
+			<family>Noto Sans Myanmar UI</family><!-- my -->
+			<family>Noto Sans Oriya UI</family><!-- or -->
+			<family>Noto Sans Sinhala UI</family><!-- si -->
+			<family>Noto Sans Tamil UI</family><!-- ta -->
+			<family>Noto Sans Telugu UI</family><!-- te -->
+			<family>Noto Sans Thai UI</family><!-- th -->
+			<family>Leelawadee UI</family><!-- bug, th, jv, km, lo -->
+			<family>Nirmala UI</family><!-- Indic -->
+			<family>Yu Gothic UI</family><!-- han (ja) -->
+			<family>Meiryo UI</family><!-- han (ja) -->
+			<family>MS UI Gothic</family><!-- han (ja) -->
+			<family>Khmer UI</family><!-- km -->
+			<family>Lao UI</family><!-- lo -->
+			<family>Microsoft YaHei UI</family><!-- han (zh-cn) -->
+			<family>Microsoft JhengHei UI</family><!-- han (zh-tw) -->
+		</prefer>
+	</alias>
+
 </fontconfig>
diff --git a/fonts.conf.in b/fonts.conf.in
index 2019923..5a1a4d0 100644
--- a/fonts.conf.in
+++ b/fonts.conf.in
@@ -69,6 +69,17 @@
 			<string>sans-serif</string>
 		</edit>
 	</match>
+<!--
+  Accept alternate 'system ui' spelling, replacing it with 'system-ui'
+-->
+	<match target="pattern">
+		<test qual="any" name="family">
+			<string>system ui</string>
+		</test>
+		<edit name="family" mode="assign" binding="same">
+			<string>system-ui</string>
+		</edit>
+	</match>
 
 <!--
   Load local system customization file