diff --git a/.changeset/moody-balloons-cheat.md b/.changeset/moody-balloons-cheat.md
new file mode 100644
index 00000000..f94d16db
--- /dev/null
+++ b/.changeset/moody-balloons-cheat.md
@@ -0,0 +1,5 @@
+---
+'mdsvex': patch
+---
+
+Replace hyphen in YAML frontmatter with underscore to prevent issues when building
diff --git a/packages/mdsvex/src/transformers/index.ts b/packages/mdsvex/src/transformers/index.ts
index 429938ea..8ca31803 100644
--- a/packages/mdsvex/src/transformers/index.ts
+++ b/packages/mdsvex/src/transformers/index.ts
@@ -332,7 +332,9 @@ export function transform_hast({
 			const fm =
 				metadata &&
 				`export const metadata = ${stringified};${newline}` +
-					`\tconst { ${Object.keys(metadata).join(', ')} } = metadata;`;
+					`\tconst { ${Object.keys(metadata)
+						.join(', ')
+						.replace(/-/g, '_')} } = metadata;`;
 
 			const frontmatter_layout =
 				metadata && (metadata.layout as string | undefined | false);