diff --git a/library/src/math/matrix.rs b/library/src/math/matrix.rs
index 8fba10e71..66925cda5 100644
--- a/library/src/math/matrix.rs
+++ b/library/src/math/matrix.rs
@@ -24,8 +24,8 @@ pub struct VecElem {
     /// #set math.vec(delim: "[")
     /// $ vec(1, 2) $
     /// ```
-    #[default(Delimiter::Paren)]
-    pub delim: Delimiter,
+    #[default(Some(Delimiter::Paren))]
+    pub delim: Option<Delimiter>,
 
     /// The elements of the vector.
     #[variadic]
@@ -39,8 +39,8 @@ impl LayoutMath for VecElem {
         layout_delimiters(
             ctx,
             frame,
-            Some(delim.open()),
-            Some(delim.close()),
+            delim.map(Delimiter::open),
+            delim.map(Delimiter::close),
             self.span(),
         )
     }
@@ -76,8 +76,8 @@ pub struct MatElem {
     /// #set math.mat(delim: "[")
     /// $ mat(1, 2; 3, 4) $
     /// ```
-    #[default(Delimiter::Paren)]
-    pub delim: Delimiter,
+    #[default(Some(Delimiter::Paren))]
+    pub delim: Option<Delimiter>,
 
     /// An array of arrays with the rows of the matrix.
     ///
@@ -121,8 +121,8 @@ impl LayoutMath for MatElem {
         layout_delimiters(
             ctx,
             frame,
-            Some(delim.open()),
-            Some(delim.close()),
+            delim.map(Delimiter::open),
+            delim.map(Delimiter::close),
             self.span(),
         )
     }
diff --git a/tests/ref/math/matrix.png b/tests/ref/math/matrix.png
index 59e3a7b09..f74384a36 100644
Binary files a/tests/ref/math/matrix.png and b/tests/ref/math/matrix.png differ
diff --git a/tests/typ/math/matrix.typ b/tests/typ/math/matrix.typ
index a828e4b41..e57e102e4 100644
--- a/tests/typ/math/matrix.typ
+++ b/tests/typ/math/matrix.typ
@@ -32,6 +32,7 @@ $ mat(
 // Test alternative delimiter with set rule.
 #set math.mat(delim: "[")
 $ mat(1, 2; 3, 4) $
+$ a + mat(delim: #none, 1, 2; 3, 4) + b $
 
 ---
 // Test alternative math delimiter directly in call.
diff --git a/tests/typ/math/vec.typ b/tests/typ/math/vec.typ
index 198a1d154..445b8104c 100644
--- a/tests/typ/math/vec.typ
+++ b/tests/typ/math/vec.typ
@@ -10,5 +10,5 @@ $ v = vec(1, 2+3, 4) $
 $ vec(1, 2) $
 
 ---
-// Error: 22-25 expected "(", "[", "{", "|", or "||"
+// Error: 22-25 expected "(", "[", "{", "|", "||", or none
 #set math.vec(delim: "%")