diff --git a/doc/articles/troubleshooting.md b/doc/articles/troubleshooting.md
index ad46d7114..9582fd500 100644
--- a/doc/articles/troubleshooting.md
+++ b/doc/articles/troubleshooting.md
@@ -345,3 +345,14 @@ composer update
```
See also https://github.com/composer/composer/issues/4180 for more information.
+
+## Zip archives are being reported as corrupted or not unpacked correctly.
+
+Composer can unpack zipballs using either a system-provided `unzip` utility or PHP's
+native `ZipArchiver` class, preferring the first. The `ZipArchiver` class however is
+known to occassionally report valid zip files as corrupted, and does not support certain
+advanced features with permissions and symlinks.
+
+If you have issues with zip files you should install a native implementation of unzip
+and verify whether the problem persists. If so it is likely a real issue in the file
+itself and you should contact the provider.
diff --git a/src/Composer/Downloader/ZipDownloader.php b/src/Composer/Downloader/ZipDownloader.php
index aaa45200b..5278be91b 100644
--- a/src/Composer/Downloader/ZipDownloader.php
+++ b/src/Composer/Downloader/ZipDownloader.php
@@ -98,7 +98,10 @@ class ZipDownloader extends ArchiveDownloader
}
if (true !== $zipArchive->extractTo($path)) {
- throw new \RuntimeException("There was an error extracting the ZIP file. Corrupt file?");
+ $this->io->writeError("As there is no 'unzip' command installed zip files are being unpacked using the PHP zip extension.");
+ $this->io->writeError("This may cause invalid reports of corrupted archives. Installing 'unzip' may remediate them.");
+
+ throw new \RuntimeException("There was an error extracting the ZIP file, it is either corrupted or using an invalid format");
}
$zipArchive->close();