diff --git a/src/lib/guardrails/videoBridgeFrameContract.ts b/src/lib/guardrails/videoBridgeFrameContract.ts
index b1957fafb5..996c3c5ea3 100644
--- a/src/lib/guardrails/videoBridgeFrameContract.ts
+++ b/src/lib/guardrails/videoBridgeFrameContract.ts
@@ -1,6 +1,10 @@
 export const JPEG_FRAME_DATA_URI_PREFIX = "data:image/jpeg;base64,";
 
-const JPEG_FRAME_DATA_URI_PATTERN = /^data:image\/jpeg;base64,([A-Za-z0-9+/=]+)$/i;
+// Derived from the exported prefix so the two can never drift apart.
+const JPEG_FRAME_DATA_URI_PATTERN = new RegExp(
+  `^${JPEG_FRAME_DATA_URI_PREFIX.replace(/[.*+?^${}()|[\]\\/]/g, "\\$&")}([A-Za-z0-9+/=]+)$`,
+  "i"
+);
 
 function matchJpegFrame(dataUri: string): string {
   const match = JPEG_FRAME_DATA_URI_PATTERN.exec(dataUri);
@@ -8,7 +12,10 @@ function matchJpegFrame(dataUri: string): string {
   return match[1];
 }
 
-/** Throws on any non-JPEG or base64-invalid input; the single frame decode used by every video module. */
+/**
+ * Throws on any non-JPEG or base64-invalid input; the single frame decode used by every
+ * video module.
+ */
 export function decodeJpegFrameDataUri(dataUri: string): Buffer {
   return Buffer.from(matchJpegFrame(dataUri), "base64");
 }