diff --git a/CHANGELOG.md b/CHANGELOG.md
index b6601e6..30dda3e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,15 @@ Versions before 0.8.0 are in the [git tags](https://github.com/WireCatLabs/cli-b
 Every entry says what changed as a caller sees it, why, and what to watch for — the rules are
 [`docs/dev/CONVENTIONS.md`](docs/dev/CONVENTIONS.md#the-changelog).
 
+## Unreleased
+
+### Added
+
+- **A query that fails on an unquoted value with an operator in it says to quote it.** `url:a.com/x?y=1` used to
+  fail with only `query.invalid-syntax at position 14`: `/`, `?`, `=` and `:` are query syntax. The error now ends
+  with `put the value in quotes: url:"a.com/x?y=1"`, also in `details.alternative`. A failure that already carries
+  an alternative keeps its own.
+
 ## 0.38.0 — 16.10.2026
 
 ### Added
diff --git a/src/query/parser.test.ts b/src/query/parser.test.ts
index f27f006..e44e551 100644
--- a/src/query/parser.test.ts
+++ b/src/query/parser.test.ts
@@ -84,6 +84,16 @@ describe("a list's query", () => {
     expect(failure(() => parseLucene('"open')).message).toMatch(/^query: /)
   })
 
+  it("tells to quote a value that holds an operator", () => {
+    expect(failure(() => parseLucene("link:click?id=1")).message).toBe(
+      'query: query.invalid-syntax at position 14 — put the value in quotes: link:"click?id=1"',
+    )
+    expect(failure(() => parseLucene("alpha url:a.com/x")).details.alternative).toBe(
+      'put the value in quotes: url:"a.com/x"',
+    )
+    expect(failure(() => parseLucene('"open')).details.alternative).toBeUndefined()
+  })
+
   it("reads the terms lists need: quoted values with a colon, comparisons, presence, relative dates", () => {
     expect(failure(() => parseLucene("subject:note:42", { defaultField: "none" })).details.reason).toBe(
       "query.invalid-syntax",
diff --git a/src/query/parser.ts b/src/query/parser.ts
index 26dbda9..b62738a 100644
--- a/src/query/parser.ts
+++ b/src/query/parser.ts
@@ -133,8 +133,20 @@ export interface ParseOptions extends QueryContext {
   defaultField?: string
 }
 
+// A value written without quotes that holds an operator (`url:a.com/x?y=1`) fails at a character the reader does not
+// see as special; name the fix instead.
+const quoteHint = (text: string, at: number): string | undefined => {
+  for (const match of text.matchAll(/(?<=^|[\s(])([\p{L}\p{N}_.-]+):([^\s"()]+)/gu)) {
+    const [whole, field, value = ""] = match
+    if (at < match.index || at > match.index + whole.length) continue
+    return /[:=/?*~^@<>![\]{}\\]/u.test(value) ? `put the value in quotes: ${field}:"${value}"` : undefined
+  }
+  return undefined
+}
+
 export const parseLucene = (text: string, { defaultField = "text", ...context }: ParseOptions = {}): QueryAst => {
-  const fail: Fail = (reason, span, alternative) => queryError(reason, span, alternative, context)
+  const fail: Fail = (reason, span, alternative) =>
+    queryError(reason, span, alternative ?? quoteHint(text, span.start), context)
   if (text.length > QUERY_LIMITS.bytes || new TextEncoder().encode(text).length > QUERY_LIMITS.bytes)
     fail("query.too-large", { start: 0, end: text.length })
   const tokens = tokensOf(text, fail)