diff --git a/src/doc/directives.ts b/src/doc/directives.ts
index 4978c07f..add18fcd 100644
--- a/src/doc/directives.ts
+++ b/src/doc/directives.ts
@@ -146,7 +146,14 @@ export class Directives {
     const [, handle, suffix] = source.match(/^(.*!)([^!]*)$/) as string[]
     if (!suffix) onError(`The ${source} tag has no suffix`)
     const prefix = this.tags[handle]
-    if (prefix) return prefix + decodeURIComponent(suffix)
+    if (prefix) {
+      try {
+        return prefix + decodeURIComponent(suffix)
+      } catch (error) {
+        onError(String(error))
+        return null
+      }
+    }
     if (handle === '!') return source // local tag
 
     onError(`Could not resolve tag: ${source}`)
diff --git a/tests/doc/types.ts b/tests/doc/types.ts
index c03668be..28f2180b 100644
--- a/tests/doc/types.ts
+++ b/tests/doc/types.ts
@@ -106,6 +106,12 @@ describe('tags', () => {
         expect(doc.errors[0].code).toBe('MISSING_CHAR')
       })
     }
+
+    test('malformed URI (eemeli/yaml#498)', () => {
+      const doc = parseDocument('!!%ee 0')
+      expect(doc.errors).toHaveLength(1)
+      expect(doc.errors[0].message).toMatch('URIError')
+    })
   })
 
   test('eemeli/yaml#97', () => {