diff --git a/testsuite/tests/input/tex/Newcommand.test.ts b/testsuite/tests/input/tex/Newcommand.test.ts
index 8010f58a6..c430f744b 100644
--- a/testsuite/tests/input/tex/Newcommand.test.ts
+++ b/testsuite/tests/input/tex/Newcommand.test.ts
@@ -728,4 +728,4 @@ describe('Nested Environments', () => {
 /**********************************************************************************/
 /**********************************************************************************/
 
-afterAll(() => getTokens('newcommand'));
+  afterAll(() => getTokens('newcommand'));
diff --git a/testsuite/tests/input/tex/__snapshots__/Mathtools.test.ts.snap b/testsuite/tests/input/tex/__snapshots__/Mathtools.test.ts.snap
index cd5d5956b..51e18f233 100644
--- a/testsuite/tests/input/tex/__snapshots__/Mathtools.test.ts.snap
+++ b/testsuite/tests/input/tex/__snapshots__/Mathtools.test.ts.snap
@@ -2298,11 +2298,11 @@ exports[`Mathtools Paired Delimiters DeclarePairedDelimiterX 1`] = `
 exports[`Mathtools Paired Delimiters DeclarePairedDelimiterXPP 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\DeclarePairedDelimiterXPP\\x[1]{A}{\\lvert}{\\rvert}{B}{a#1b} \\x{X}" display="block">
   <mi data-latex="A">A</mi>
-  <mo data-mjx-texclass="OPEN" data-latex="\\lvert">|</mo>
+  <mo data-mjx-texclass="OPEN" stretchy="false" data-latex="\\lvert">|</mo>
   <mi data-latex="a">a</mi>
   <mi data-latex="X">X</mi>
   <mi data-latex="b">b</mi>
-  <mo data-mjx-texclass="CLOSE" data-latex="\\rvert">|</mo>
+  <mo data-mjx-texclass="CLOSE" stretchy="false" data-latex="\\rvert">|</mo>
   <mi data-latex="B">B</mi>
 </math>"
 `;
diff --git a/testsuite/tests/input/tex/__snapshots__/Newcommand.test.ts.snap b/testsuite/tests/input/tex/__snapshots__/Newcommand.test.ts.snap
index 3e42f8a6d..35f2f7978 100644
--- a/testsuite/tests/input/tex/__snapshots__/Newcommand.test.ts.snap
+++ b/testsuite/tests/input/tex/__snapshots__/Newcommand.test.ts.snap
@@ -80,7 +80,7 @@ exports[`Nested Environments Newenvironment with Begin 1`] = `
 exports[`Newcommand Ams Let Bar 1`] = `
 "<math xmlns="http://www.w3.org/1998/Math/MathML" data-latex="\\let\\b\\lvert\\let\\lvert\\langle\\vert\\b\\lvert" display="block">
   <mo data-mjx-texclass="ORD" fence="false" stretchy="false" data-latex="\\vert">|</mo>
-  <mo data-mjx-texclass="OPEN" data-latex="\\b">|</mo>
+  <mo data-mjx-texclass="OPEN" stretchy="false" data-latex="\\b">|</mo>
   <mo fence="false" stretchy="false" data-latex="\\lvert">&#x27E8;</mo>
 </math>"
 `;
diff --git a/testsuite/tests/input/tex/__snapshots__/Physics.test.ts.snap b/testsuite/tests/input/tex/__snapshots__/Physics.test.ts.snap
index 6764e3b9f..218039580 100644
--- a/testsuite/tests/input/tex/__snapshots__/Physics.test.ts.snap
+++ b/testsuite/tests/input/tex/__snapshots__/Physics.test.ts.snap
@@ -6566,7 +6566,7 @@ exports[`Physics6_0 BraKet_Bra_4 1`] = `
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{a}{b}}">
     <mfrac data-latex="\\frac{a}{b}">
       <mi data-latex="a">a</mi>
@@ -6586,7 +6586,7 @@ exports[`Physics6_0 BraKet_Bra_5 1`] = `
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{a}{b}}">
     <mfrac data-latex="\\frac{a}{b}">
       <mi data-latex="a">a</mi>
@@ -6817,7 +6817,7 @@ exports[`Physics6_1 BraKet_Braket_2 1`] = `
   <mrow data-mjx-texclass="ORD" data-latex="{A}">
     <mi data-latex="A">A</mi>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{A}">
     <mi data-latex="A">A</mi>
   </mrow>
@@ -6834,7 +6834,7 @@ exports[`Physics6_1 BraKet_Braket_3 1`] = `
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{a}{b}}">
     <mfrac data-latex="\\frac{a}{b}">
       <mi data-latex="a">a</mi>
@@ -6869,7 +6869,7 @@ exports[`Physics6_1 BraKet_Braket_5 1`] = `
   <mrow data-mjx-texclass="ORD" data-latex="{a}">
     <mi data-latex="a">a</mi>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{a}">
     <mi data-latex="a">a</mi>
   </mrow>
@@ -6925,7 +6925,7 @@ exports[`Physics6_1 BraKet_Braket_8 1`] = `
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{A}">
     <mi data-latex="A">A</mi>
   </mrow>
@@ -6967,7 +6967,7 @@ exports[`Physics6_1 BraKet_Braket_10 1`] = `
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{a}{b}}">
     <mfrac data-latex="\\frac{a}{b}">
       <mi data-latex="a">a</mi>
@@ -7007,7 +7007,7 @@ exports[`Physics6_1 BraKet_Braket_12 1`] = `
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{}"></mrow>
   <mo fence="false" stretchy="false" data-latex="\\braket*{\\frac{a}{b}}{}">&#x27E9;</mo>
 </math>"
@@ -7252,7 +7252,7 @@ exports[`Physics6_2 BraKet_Ketbra_10 1`] = `
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\ketbra*{\\frac{a}{b}}">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\ketbra*{\\frac{a}{b}}">|</mo>
   <mi data-latex="A">A</mi>
 </math>"
 `;
@@ -7495,11 +7495,11 @@ exports[`Physics6_3 BraKet_Expect_6 1`] = `
       <mi data-latex="B">B</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{A}">
     <mi data-latex="A">A</mi>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{A}{B}}">
     <mfrac data-latex="\\frac{A}{B}">
       <mi data-latex="A">A</mi>
@@ -7606,11 +7606,11 @@ exports[`Physics6_3 BraKet_Expect_11 1`] = `
       <mi data-latex="B">B</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{A}">
     <mi data-latex="A">A</mi>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{A}{B}}">
     <mfrac data-latex="\\frac{A}{B}">
       <mi data-latex="A">A</mi>
@@ -7720,14 +7720,14 @@ exports[`Physics6_3 BraKet_Expect_15 1`] = `
       <mi mathvariant="normal" data-latex="\\Phi">&#x3A6;</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{A}{B}}">
     <mfrac data-latex="\\frac{A}{B}">
       <mi data-latex="A">A</mi>
       <mi data-latex="B">B</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{\\Psi}{\\Phi}}">
     <mfrac data-latex="\\frac{\\Psi}{\\Phi}">
       <mi mathvariant="normal" data-latex="\\Psi">&#x3A8;</mi>
@@ -7874,14 +7874,14 @@ exports[`Physics6_4 BraKet_MatrixEl_4 1`] = `
   <mrow data-mjx-texclass="ORD" data-latex="{n}">
     <mi data-latex="n">n</mi>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{a}{b}}">
     <mfrac data-latex="\\frac{a}{b}">
       <mi data-latex="a">a</mi>
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{m}">
     <mi data-latex="m">m</mi>
   </mrow>
@@ -7898,14 +7898,14 @@ exports[`Physics6_4 BraKet_MatrixEl_5 1`] = `
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{a}{b}}">
     <mfrac data-latex="\\frac{a}{b}">
       <mi data-latex="a">a</mi>
       <mi data-latex="b">b</mi>
     </mfrac>
   </mrow>
-  <mo data-mjx-texclass="ORD" data-latex="\\vert">|</mo>
+  <mo data-mjx-texclass="ORD" stretchy="false" data-latex="\\vert">|</mo>
   <mrow data-mjx-texclass="ORD" data-latex="{\\frac{a}{b}}">
     <mfrac data-latex="\\frac{a}{b}">
       <mi data-latex="a">a</mi>
diff --git a/ts/input/tex/ParseMethods.ts b/ts/input/tex/ParseMethods.ts
index c3e037dde..38784b12c 100644
--- a/ts/input/tex/ParseMethods.ts
+++ b/ts/input/tex/ParseMethods.ts
@@ -195,6 +195,9 @@ const ParseMethods = {
     // @test Fenced2, Delimiter (AMS)
     def = Object.assign({ fence: false, stretchy: false }, def);
     const node = parser.create('token', 'mo', def, delim.char);
+    if (delim.char === '|') {
+      node.setProperty('keep-attrs', 'stretchy');
+    }
     parser.Push(node);
   },