diff --git a/wire-runtime-swift/src/test/swift/AnyMessageTests.swift b/wire-runtime-swift/src/test/swift/AnyMessageTests.swift
index a8dde6bd16..bd182a61f4 100644
--- a/wire-runtime-swift/src/test/swift/AnyMessageTests.swift
+++ b/wire-runtime-swift/src/test/swift/AnyMessageTests.swift
@@ -26,6 +26,14 @@ final class AnyMessageTests: XCTestCase {
         XCTAssertEqual(any.value, try ProtoEncoder().encode(person))
     }
 
+    func testPackingFieldMask() throws {
+        let fieldMask = FieldMask(paths: ["user.display_name", "photo"])
+        let any = try AnyMessage.pack(fieldMask)
+        XCTAssertEqual(any.typeURL, FieldMask.protoMessageTypeURL())
+        XCTAssertEqual(any.value, try ProtoEncoder().encode(fieldMask))
+        XCTAssertEqual(fieldMask, try any.unpack(FieldMask.self))
+    }
+
     func testUnpackingAnyToCorrectType() throws {
         let data = Data(json_data: "")
         let person = Person(name: "foo bar", id: 12345, data: data)
diff --git a/wire-runtime/api/wire-runtime.api b/wire-runtime/api/wire-runtime.api
index c8f802850f..2179e3baec 100644
--- a/wire-runtime/api/wire-runtime.api
+++ b/wire-runtime/api/wire-runtime.api
@@ -30,6 +30,7 @@ public final class com/squareup/wire/AnyMessage : com/squareup/wire/Message {
 
 public final class com/squareup/wire/AnyMessage$Companion {
 	public final fun pack (Lcom/squareup/wire/Message;)Lcom/squareup/wire/AnyMessage;
+	public final fun pack (Lcom/squareup/wire/ProtoAdapter;Ljava/lang/Object;)Lcom/squareup/wire/AnyMessage;
 }
 
 public final class com/squareup/wire/DurationKt {
diff --git a/wire-runtime/src/commonMain/kotlin/com/squareup/wire/AnyMessage.kt b/wire-runtime/src/commonMain/kotlin/com/squareup/wire/AnyMessage.kt
index dc10e0c363..9e722a2d94 100644
--- a/wire-runtime/src/commonMain/kotlin/com/squareup/wire/AnyMessage.kt
+++ b/wire-runtime/src/commonMain/kotlin/com/squareup/wire/AnyMessage.kt
@@ -29,7 +29,9 @@ import okio.ByteString
  * Example
  * ```
  * val person: Person = anyMessage.unpack(Person.ADAPTER)
- * val anyMessage: AnyMessage = AnyMessage.ADAPTER.pack(person)
+ * val anyMessage: AnyMessage = AnyMessage.pack(person)
+ * val fieldMask = FieldMask(listOf("name"))
+ * val fieldMaskAny: AnyMessage = AnyMessage.pack(ProtoAdapter.FIELD_MASK, fieldMask)
  * ```
  */
 class AnyMessage(
@@ -82,6 +84,12 @@ class AnyMessage(
       return AnyMessage(typeUrl, message.encodeByteString())
     }
 
+    fun <T> pack(adapter: ProtoAdapter<T>, value: T): AnyMessage {
+      val typeUrl = adapter.typeUrl
+        ?: error("recompile ${adapter.type ?: "type"} to use it with AnyMessage")
+      return AnyMessage(typeUrl, adapter.encodeByteString(value))
+    }
+
     @JvmField
     val ADAPTER: ProtoAdapter<AnyMessage> = object : ProtoAdapter<AnyMessage>(
       FieldEncoding.LENGTH_DELIMITED,
diff --git a/wire-tests/multiplatform/src/commonTest/kotlin/com/squareup/wire/AnyMessageTest.kt b/wire-tests/multiplatform/src/commonTest/kotlin/com/squareup/wire/AnyMessageTest.kt
index 71b654eb82..5667d97029 100644
--- a/wire-tests/multiplatform/src/commonTest/kotlin/com/squareup/wire/AnyMessageTest.kt
+++ b/wire-tests/multiplatform/src/commonTest/kotlin/com/squareup/wire/AnyMessageTest.kt
@@ -59,6 +59,15 @@ class AnyMessageTest {
     assertThat(usesAny.just_one.unpackOrNull(ProtoAdapter.BOOL)).isEqualTo(null)
   }
 
+  @Test fun packAndUnpackRuntimeValue() {
+    val fieldMask = FieldMask(listOf("user.display_name", "photo"))
+    val any = AnyMessage.pack(ProtoAdapter.FIELD_MASK, fieldMask)
+
+    assertThat(any.typeUrl).isEqualTo(ProtoAdapter.FIELD_MASK.typeUrl)
+    assertThat(any.value).isEqualTo(ProtoAdapter.FIELD_MASK.encodeByteString(fieldMask))
+    assertThat(any.unpack(ProtoAdapter.FIELD_MASK)).isEqualTo(fieldMask)
+  }
+
   @Test fun encodeAndDecode() {
     val hex = "0a430a3d747970652e676f6f676c65617069732e636f6d2f73717561726575702e70726f746f732e6b" +
       "6f746c696e2e6564676563617365732e4f6e654669656c641202080312430a3d747970652e676f6f676c6561" +