diff --git a/CHANGELOG.md b/CHANGELOG.md
index dd03c72..902575e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,12 @@
 
 ### New in `sym`
 
+- Mathematical symbols
+  - `union.serif`: ∪︀
+  - `union.sq.serif`: ⊔︀
+  - `inter.serif`: ∩︀
+  - `inter.sq.serif`: ⊓︀
+
 - Currency
   - `riyal`: ⃁
 
diff --git a/src/modules/sym.txt b/src/modules/sym.txt
index 8cb5711..a3fb015 100644
--- a/src/modules/sym.txt
+++ b/src/modules/sym.txt
@@ -503,6 +503,7 @@ supset ⊃
   .sq ⊐
   .sq.neq ⋥
 union ∪
+  .serif ∪\vs{1}
   .arrow ⊌
   .big ⋃
   .dot ⊍
@@ -513,14 +514,17 @@ union ∪
   .plus ⊎
   .plus.big ⨄
   .sq ⊔
+  .sq.serif ⊔\vs{1}
   .sq.big ⨆
   .sq.double ⩏
 inter ∩
+  .serif ∩\vs{1}
   .and ⩄
   .big ⋂
   .dot ⩀
   .double ⋒
   .sq ⊓
+  .sq.serif ⊓\vs{1}
   .sq.big ⨅
   .sq.double ⩎
 @deprecated: `sect` is deprecated, use `inter` instead