diff --git a/packages/myst-parser/tests/roles/si.yml b/packages/myst-parser/tests/roles/si.yml
index 606123195..7e5e84a48 100644
--- a/packages/myst-parser/tests/roles/si.yml
+++ b/packages/myst-parser/tests/roles/si.yml
@@ -33,7 +33,6 @@ cases:
                   units: [hertz]
                   value: 100 Hz
 
-
   - title: decimal number parses
     markdown: '{si}`1.345e10 <\hertz>`'
     mdast:
@@ -50,4 +49,4 @@ cases:
                   number: '1.345e10'
                   unit: Hz
                   units: [hertz]
-                  value: 1.345e10 Hz
\ No newline at end of file
+                  value: 1.345e10 Hz
diff --git a/packages/myst-roles/src/si.ts b/packages/myst-roles/src/si.ts
index f15b35933..eaf4ca212 100644
--- a/packages/myst-roles/src/si.ts
+++ b/packages/myst-roles/src/si.ts
@@ -14,7 +14,7 @@ export const siRole: RoleSpec = {
       return [{ type: 'si', error: true, value }];
     }
     const number = match[1];
-    const commands = match[match.length-1];
+    const commands = match[match.length - 1];
     const parsed = [...commands.matchAll(/\\([a-zA-Z]+)/g)];
     const units = parsed.filter((c) => !!c).map(([, c]) => c);
     const translated = units.map((c) => UNITS[c] ?? c);