diff --git a/CHANGELOG.md b/CHANGELOG.md
index b1e03b84271..332693bafba 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -56,6 +56,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Media/images: keep HEIC/HEIF attachments fail-closed when optional Sharp conversion is unavailable instead of sending originals that still need conversion. Thanks @vincentkoc.
 - Telegram/streaming: sanitize tool-progress draft preview backticks before shared compaction, so long backtick-heavy progress text still renders inside the safe code-formatted preview instead of collapsing to an ellipsis.
 - UI/chat: remove the unsupported `line-clamp` declaration from the chat queue text rule to eliminate Firefox console noise without changing visible truncation behavior. Thanks @ZanderH-code.
 - Agents/Pi: suppress persistence for synthetic mid-turn overflow continuation prompts, so transcript-retry recovery does not write the "continue from transcript" prompt as a new user turn. Thanks @vincentkoc.
diff --git a/src/media/web-media.test.ts b/src/media/web-media.test.ts
index 634b1763fe0..8ac66305273 100644
--- a/src/media/web-media.test.ts
+++ b/src/media/web-media.test.ts
@@ -176,7 +176,9 @@ describe("loadWebMedia", () => {
         throw new Error("should not optimize png");
       }),
       resizeToJpeg: vi.fn(async () => {
-        throw new Error("should not resize jpeg");
+        throw new Error(
+          "Optional dependency sharp is required for image attachment processing | Cannot find package 'sharp' imported from image-ops.js",
+        );
       }),
     }));
     try {
@@ -210,6 +212,17 @@ describe("loadWebMedia", () => {
     });
   });
 
+  it("does not send original HEIC media when optional sharp conversion is unavailable", async () => {
+    await withUnavailableImageOptimizer(async () => {
+      const heicFile = path.join(fixtureRoot, "photo.heic");
+      await fs.writeFile(heicFile, Buffer.from("heic-source"));
+      const { loadWebMedia: loadWebMediaWithMissingOptimizer } = await import("./web-media.js");
+      await expect(
+        loadWebMediaWithMissingOptimizer(heicFile, createLocalWebMediaOptions()),
+      ).rejects.toThrow(/Optional dependency sharp is required/);
+    });
+  });
+
   it("resolves relative local media paths against the provided workspace directory", async () => {
     const result = await loadWebMedia("chart.png", {
       maxBytes: 1024 * 1024,
diff --git a/src/media/web-media.ts b/src/media/web-media.ts
index f77661680ff..edf37dbad35 100644
--- a/src/media/web-media.ts
+++ b/src/media/web-media.ts
@@ -413,7 +413,11 @@ async function loadWebMediaInternal(
     try {
       optimized = await optimizeImageWithFallback({ buffer, cap, meta });
     } catch (err) {
-      if (isOptionalImageOptimizerUnavailable(err) && buffer.length <= cap) {
+      if (
+        isOptionalImageOptimizerUnavailable(err) &&
+        !isHeicSource(meta ?? {}) &&
+        buffer.length <= cap
+      ) {
         if (shouldLogVerbose()) {
           logVerbose(
             `Image optimizer unavailable; sending original ${formatMb(buffer.length)}MB media without optimization`,