diff --git a/lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/messages/EnvelopeContentValidator.kt b/lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/messages/EnvelopeContentValidator.kt
index e2b24e0caa..d64f4f0188 100644
--- a/lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/messages/EnvelopeContentValidator.kt
+++ b/lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/messages/EnvelopeContentValidator.kt
@@ -414,7 +414,10 @@ object EnvelopeContentValidator {
       return Result.Invalid("[StoryMessage] Style body range is missing a start or length!")
     }
 
-    if (storyMessage.bodyRanges.hasInvalidBounds(storyMessage.textAttachment?.text)) {
+    // Body ranges apply to the text of a text story, or to the caption of a media story.
+    val storyText: String? = storyMessage.textAttachment?.text ?: storyMessage.fileAttachment?.caption
+
+    if (storyMessage.bodyRanges.hasInvalidBounds(storyText)) {
       return Result.Invalid("[StoryMessage] Body range with out-of-bounds start/length!")
     }
 
diff --git a/lib/libsignal-service/src/test/java/org/whispersystems/signalservice/api/messages/EnvelopeContentValidatorTest.kt b/lib/libsignal-service/src/test/java/org/whispersystems/signalservice/api/messages/EnvelopeContentValidatorTest.kt
index 7f480dacc2..96c6ad2a92 100644
--- a/lib/libsignal-service/src/test/java/org/whispersystems/signalservice/api/messages/EnvelopeContentValidatorTest.kt
+++ b/lib/libsignal-service/src/test/java/org/whispersystems/signalservice/api/messages/EnvelopeContentValidatorTest.kt
@@ -779,6 +779,36 @@ class EnvelopeContentValidatorTest {
     assert(result is EnvelopeContentValidator.Result.Valid)
   }
 
+  @Test
+  fun `validate - ensure story body range within the bounds of the file attachment caption is marked valid`() {
+    val content = Content(
+      storyMessage = StoryMessage(
+        fileAttachment = AttachmentPointer(cdnKey = "key", caption = "abc"),
+        bodyRanges = listOf(
+          BodyRange(start = 0, length = 3, style = BodyRange.Style.ITALIC)
+        )
+      )
+    )
+
+    val result = EnvelopeContentValidator.validate(Envelope(clientTimestamp = 1234), content, SELF_ACI, CiphertextMessage.WHISPER_TYPE)
+    assert(result is EnvelopeContentValidator.Result.Valid)
+  }
+
+  @Test
+  fun `validate - ensure story body range extending past the end of the file attachment caption is marked invalid`() {
+    val content = Content(
+      storyMessage = StoryMessage(
+        fileAttachment = AttachmentPointer(cdnKey = "key", caption = "abc"),
+        bodyRanges = listOf(
+          BodyRange(start = 2, length = 10, style = BodyRange.Style.ITALIC)
+        )
+      )
+    )
+
+    val result = EnvelopeContentValidator.validate(Envelope(clientTimestamp = 1234), content, SELF_ACI, CiphertextMessage.WHISPER_TYPE)
+    assert(result is EnvelopeContentValidator.Result.Invalid)
+  }
+
   @Test
   fun `validate - ensure story context with a valid author but missing sentTimestamp is marked invalid`() {
     val content = Content(