diff --git a/var/spack/repos/builtin/packages/squashfs/package.py b/var/spack/repos/builtin/packages/squashfs/package.py
index ae6fc205ae..81e31a704c 100644
--- a/var/spack/repos/builtin/packages/squashfs/package.py
+++ b/var/spack/repos/builtin/packages/squashfs/package.py
@@ -29,4 +29,4 @@ def build(self, spec, prefix):
 
     def install(self, spec, prefix):
         with working_dir('squashfs-tools'):
-            make('install', 'INSTALL_DIR=%s' % prefix, parallel=False)
+            make('install', 'INSTALL_DIR=%s' % prefix.bin, parallel=False)