diff --git a/src/go/GoBinaryImage.ts b/src/go/GoBinaryImage.ts
index 03d0866ab..4a845c197 100644
--- a/src/go/GoBinaryImage.ts
+++ b/src/go/GoBinaryImage.ts
@@ -8,6 +8,10 @@ import {
   type GoBinaryContainer,
   type GoFileMapping,
 } from "./GoBinaryContainer.js";
+import {
+  classifyFatContainerIdentity,
+  readFatContainerHeader,
+} from "../domain/apple/machoContainer.js";
 import { readGoElfImage } from "./GoElfImage.js";
 import { readGoMachoImage } from "./GoMachoImage.js";
 import { readGoPeImage } from "./GoPeImage.js";
@@ -187,11 +191,27 @@ const readContainer = (bytes: Buffer): GoBinaryContainer => {
     return readGoPeImage(bytes);
   if (bytes.length >= 4) {
     const magic = bytes.readUInt32BE();
-    if ([0xcafebabe, 0xcafebabf, 0xbebafeca, 0xbfbafeca].includes(magic))
-      throw new GoBinaryFormatFailure(
-        "unsupported",
-        "Universal/fat Mach-O containers require selecting a thin slice",
-      );
+    if ([0xcafebabe, 0xcafebabf, 0xbebafeca, 0xbfbafeca].includes(magic)) {
+      const fatHeader = readFatContainerHeader(bytes, bytes.length);
+      if (fatHeader.state === "malformed")
+        throw new GoBinaryFormatFailure("malformed", fatHeader.reason);
+      const identity =
+        fatHeader.state === "parsed"
+          ? classifyFatContainerIdentity(fatHeader, (offset) => {
+              if (offset >= bytes.length) return undefined;
+              if (offset + 4 > bytes.length) return null;
+              return bytes.readUInt32BE(offset);
+            })
+          : undefined;
+      // An invalid FAT-shaped table is not proof of a Mach-O container: JVM
+      // constant-pool bytes can share both the magic and a known CPU value.
+      const confirmedFatMachO = identity?.state === "mach-o";
+      if (confirmedFatMachO)
+        throw new GoBinaryFormatFailure(
+          "unsupported",
+          "Universal/fat Mach-O containers require selecting a thin slice",
+        );
+    }
     if ([0xfeedface, 0xfeedfacf, 0xcefaedfe, 0xcffaedfe].includes(magic))
       return readGoMachoImage(bytes);
   }
diff --git a/tests/boundary/go/goBinaryImage.test.ts b/tests/boundary/go/goBinaryImage.test.ts
index 24321ecc8..29f0e952c 100644
--- a/tests/boundary/go/goBinaryImage.test.ts
+++ b/tests/boundary/go/goBinaryImage.test.ts
@@ -1,4 +1,10 @@
 import { expect, it } from "vitest";
+import { javaClassFile } from "../../fixtures/javaClassFile.js";
+import {
+  CPU,
+  fatImage,
+  machoImage,
+} from "../../../src/artifacts/apple/MachoImage.fixture.js";
 import { readGoBinaryImage } from "../../../src/go/GoBinaryImage.js";
 import {
   createGoBinaryFixture,
@@ -221,6 +227,35 @@ it("distinguishes unsupported containers from malformed recognized images", () =
   expect(() => readGoBinaryImage(pe.bytes)).toThrowError(/range|truncated/i);
 });
 
+it("reports JVM class files as unsupported images instead of fat Mach-O containers", () => {
+  expect(() => readGoBinaryImage(javaClassFile())).toThrowError(
+    /Only ELF, PE, and thin Mach-O native images are supported/,
+  );
+  expect(() => readGoBinaryImage(javaClassFile(4000))).toThrowError(
+    /Only ELF, PE, and thin Mach-O native images are supported/,
+  );
+  expect(() => readGoBinaryImage(javaClassFile(4000, true))).toThrowError(
+    /Only ELF, PE, and thin Mach-O native images are supported/,
+  );
+});
+
+it("keeps the thin-slice failure for confirmed universal Mach-O containers", () => {
+  const slices = [
+    { cpu: CPU.x86_64, bytes: machoImage({ cpu: CPU.x86_64 }) },
+    { cpu: CPU.arm64, bytes: machoImage({ cpu: CPU.arm64 }) },
+  ];
+  for (const universal of [
+    fatImage(slices),
+    fatImage(slices, true),
+    fatImage(slices, false, true),
+    fatImage(slices, true, true),
+  ]) {
+    expect(() => readGoBinaryImage(Buffer.from(universal))).toThrowError(
+      /fat Mach-O containers require selecting a thin slice/,
+    );
+  }
+});
+
 it("rejects ELF header tables overlapping the native header", () => {
   const fixture = createGoBinaryFixture({ sectionless: true });
   fixture.bytes.writeBigUInt64LE(0n, 32);
diff --git a/tests/fixtures/javaClassFile.ts b/tests/fixtures/javaClassFile.ts
index 4f7727193..30f5ffc37 100644
--- a/tests/fixtures/javaClassFile.ts
+++ b/tests/fixtures/javaClassFile.ts
@@ -1,5 +1,5 @@
 /** Build a valid minimal JVM class file, optionally with an unused UTF-8 constant. */
-export const javaClassFile = (extraUtf8Bytes = 0): Buffer => {
+export const javaClassFile = (extraUtf8Bytes = 0, fatCpuLookalike = false): Buffer => {
   const utf8 = (value: string): Buffer => {
     const bytes = Buffer.from(value, "utf8");
     const entry = Buffer.alloc(3 + bytes.length);
@@ -13,6 +13,7 @@ export const javaClassFile = (extraUtf8Bytes = 0): Buffer => {
     utf8("Hello"),
     Buffer.from([7, 0, 4]),
     utf8("java/lang/Object"),
+    ...(fatCpuLookalike ? [utf8("x"), Buffer.from([3, 0, 0, 0, 7])] : []),
     ...(extraUtf8Bytes === 0 ? [] : [utf8("x".repeat(extraUtf8Bytes))]),
   ];
   const headerAndPool = Buffer.alloc(10);