diff --git a/src/sql_jsc/postgres/PostgresRequest.rs b/src/sql_jsc/postgres/PostgresRequest.rs
index f556d1e54c2a..e45aad5f4781 100644
--- a/src/sql_jsc/postgres/PostgresRequest.rs
+++ b/src/sql_jsc/postgres/PostgresRequest.rs
@@ -49,6 +49,28 @@ pub enum MessageType {
 /// The PostgreSQL wire protocol uses 16-bit integers for parameter and column counts.
 const MAX_PARAMETERS: usize = u16::MAX as usize;
 
+/// The `ERR_INVALID_ARG_TYPE` a binary encoder arm of `write_bind` throws for a
+/// value it cannot encode as `pg_type`. `index` is the 0-based parameter index.
+fn invalid_bind_value(
+    global: &JSGlobalObject,
+    index: usize,
+    pg_type: &str,
+    expected: &str,
+    value: JSValue,
+) -> AnyPostgresError {
+    let received = match JSGlobalObject::determine_specific_type(global, value) {
+        Ok(received) => received,
+        Err(err) => return js_error_to_postgres(err),
+    };
+    js_error_to_postgres(global.throw_value(global.ERR_INVALID_ARG_TYPE(format_args!(
+        "Query parameter ${} of type {} must be {}. Received {}",
+        index + 1,
+        pg_type,
+        expected,
+        received,
+    ))))
+}
+
 pub(crate) fn write_bind<Context: WriterContext>(
     name: &[u8],
     cursor_name: &BunString,
@@ -176,8 +198,17 @@ pub(crate) fn write_bind<Context: WriterContext>(
                 l.write_excluding_self()?;
             }
             types::Tag::bool => {
+                if !value.is_boolean() {
+                    return Err(invalid_bind_value(
+                        global,
+                        i,
+                        "boolean",
+                        "a boolean or a string",
+                        value,
+                    ));
+                }
                 let l = writer.length()?;
-                writer.write(&[value.to_boolean() as u8])?;
+                writer.write(&[value.as_boolean() as u8])?;
                 l.write_excluding_self()?;
             }
             types::Tag::timestamp | types::Tag::timestamptz => {
@@ -190,15 +221,13 @@ pub(crate) fn write_bind<Context: WriterContext>(
             }
             types::Tag::bytea => {
                 let Some(buf) = value.as_array_buffer(global) else {
-                    let received = JSGlobalObject::determine_specific_type(global, value)
-                        .map_err(js_error_to_postgres)?;
-                    return Err(js_error_to_postgres(global.throw_value(
-                        global.ERR_INVALID_ARG_TYPE(format_args!(
-                            "Query parameter ${} of type bytea must be a Buffer, TypedArray, ArrayBuffer or string. Received {}",
-                            i + 1,
-                            received,
-                        )),
-                    )));
+                    return Err(invalid_bind_value(
+                        global,
+                        i,
+                        "bytea",
+                        "a Buffer, TypedArray, ArrayBuffer or string",
+                        value,
+                    ));
                 };
                 let bytes = buf.byte_slice();
                 let l = writer.length()?;
diff --git a/test/js/sql/postgres-bool-bind.test.ts b/test/js/sql/postgres-bool-bind.test.ts
new file mode 100644
index 000000000000..8757ddd02b8e
--- /dev/null
+++ b/test/js/sql/postgres-bool-bind.test.ts
@@ -0,0 +1,113 @@
+// Binding a JS value to a parameter the server types as `boolean` (OID 16): a
+// bool column, `$1::bool`, `where flag = $1`. Bun sends a boolean parameter in
+// binary format, so the value has to be a JS boolean, or a string (sent as
+// text, parsed by the server). Bun declares no type for an object, array, Date
+// or function, the server infers `boolean` from the context, and the binary
+// encoder used to write `ToBoolean(value)`: `[]`, `{ enabled: false }`, an
+// Invalid Date and a Temporal value were all stored as `true` with no error.
+import { SQL } from "bun";
+import { expect, test } from "bun:test";
+import { describeWithContainer } from "harness";
+
+describeWithContainer("postgres", { image: "postgres_plain" }, container => {
+  const connect = () =>
+    new SQL({
+      url: `postgres://bun_sql_test@${container.host}:${container.port}/bun_sql_test`,
+      max: 1,
+    });
+
+  const rejected: [string, unknown, string][] = [
+    ["{ enabled: false }", { enabled: false }, "an instance of Object"],
+    ["[]", [], "an instance of Array"],
+    ["[1, 2]", [1, 2], "an instance of Array"],
+    ["Invalid Date", new Date(NaN), "an instance of Date"],
+    ["Date", new Date(0), "an instance of Date"],
+    [
+      "function",
+      function enabled() {
+        return false;
+      },
+      "function enabled",
+    ],
+    ["Int32Array", new Int32Array([1]), "an instance of Int32Array"],
+  ];
+  if (typeof Temporal !== "undefined") {
+    rejected.push(["Temporal.PlainDate", Temporal.PlainDate.from("2024-05-06"), "an instance of PlainDate"]);
+  }
+
+  // One connection per case: after a bind-time throw the partial Bind message
+  // stays in the write buffer and the next query on that connection fails
+  // (#34732), the same as for the other encoder arms.
+  test.each(rejected)("%s bound to a boolean column rejects instead of storing true", async (_, value, received) => {
+    await container.ready;
+    await using sql = connect();
+    await sql`create temp table bool_bind (id int, b bool)`;
+    const err: any = await sql`insert into bool_bind (id, b) values (${1}, ${value}) returning b`.then(
+      rows => rows,
+      e => e,
+    );
+    expect(err).toBeInstanceOf(TypeError);
+    expect(err.code).toBe("ERR_INVALID_ARG_TYPE");
+    expect(err.message).toBe(`Query parameter $2 of type boolean must be a boolean or a string. Received ${received}`);
+  });
+
+  test("a cast and a comparison type the parameter as boolean too", async () => {
+    await container.ready;
+    {
+      await using sql = connect();
+      const err: any = await sql`select ${{ a: 1 }}::bool as v`.then(
+        rows => rows,
+        e => e,
+      );
+      expect(err?.message).toBe(
+        "Query parameter $1 of type boolean must be a boolean or a string. Received an instance of Object",
+      );
+    }
+    {
+      await using sql = connect();
+      const err: any = await sql`select 1 as v where true = ${[]}`.then(
+        rows => rows,
+        e => e,
+      );
+      expect(err?.message).toBe(
+        "Query parameter $1 of type boolean must be a boolean or a string. Received an instance of Array",
+      );
+    }
+  });
+
+  test("booleans, null and strings bound to a boolean column still work", async () => {
+    await container.ready;
+    await using sql = connect();
+    await sql`create temp table bool_bind (id int, b bool)`;
+    const values = [true, false, null, undefined, "t", "f", "true", "false", "yes", "off", "1", "0"];
+    for (const [id, b] of values.entries()) {
+      await sql`insert into bool_bind (id, b) values (${id}, ${b})`;
+    }
+    expect(await sql`select id, b from bool_bind order by id`).toEqual([
+      { id: 0, b: true },
+      { id: 1, b: false },
+      { id: 2, b: null },
+      { id: 3, b: null },
+      { id: 4, b: true },
+      { id: 5, b: false },
+      { id: 6, b: true },
+      { id: 7, b: false },
+      { id: 8, b: true },
+      { id: 9, b: false },
+      { id: 10, b: true },
+      { id: 11, b: false },
+    ]);
+    // A string the server cannot parse as a boolean is still a server error,
+    // and the connection stays usable after it.
+    const err = await sql`insert into bool_bind (id, b) values (99, ${"garbage"})`.catch(e => e);
+    expect([err?.code, err?.errno]).toEqual(["ERR_POSTGRES_SERVER_ERROR", "22P02"]);
+    expect(await sql`select id from bool_bind where b = ${true} order by id`).toEqual([
+      { id: 0 },
+      { id: 4 },
+      { id: 6 },
+      { id: 8 },
+      { id: 10 },
+    ]);
+    expect(await sql`select ${false}::bool as v, ${true}::bool as w`).toEqual([{ v: false, w: true }]);
+  });
+});