diff --git a/src/cmd/link/internal/ld/config.go b/src/cmd/link/internal/ld/config.go
index 75fddc6a38e..ae0d7520ebc 100644
--- a/src/cmd/link/internal/ld/config.go
+++ b/src/cmd/link/internal/ld/config.go
@@ -205,6 +205,10 @@ func mustLinkExternal(ctxt *Link) (res bool, reason string) {
 		// doesn't work. Test case is "go test runtime/cgo".
 		return true, buildcfg.GOOS + " does not support internal cgo"
 	}
+	if iscgo && buildcfg.GOOS == "windows" && buildcfg.GOARCH == "arm64" {
+		// windows/arm64 internal linking is not implemented.
+		return true, buildcfg.GOOS + "/" + buildcfg.GOARCH + " does not support internal cgo"
+	}
 
 	// When the race flag is set, the LLVM tsan relocatable file is linked
 	// into the final binary, which means external linking is required because
diff --git a/src/cmd/link/internal/ld/lib.go b/src/cmd/link/internal/ld/lib.go
index d2dc3fb175b..adf1669cf26 100644
--- a/src/cmd/link/internal/ld/lib.go
+++ b/src/cmd/link/internal/ld/lib.go
@@ -1868,7 +1868,7 @@ func ldobj(ctxt *Link, f *bio.Reader, lib *sym.Library, length int64, pn string,
 			return nil
 		}
 
-		Errorf(nil, "%s: not an object file", pn)
+		Errorf(nil, "%s: not an object file: @%d %02x%02x%02x%02x", pn, start, c1, c2, c3, c4)
 		return nil
 	}