diff --git a/lib/spack/spack/util/spack_yaml.py b/lib/spack/spack/util/spack_yaml.py
index 264d5414de7b32954ae0723d3c9982fbda6233ef..1d92d59ad28425423fb34508246c85a4e1657000 100644
--- a/lib/spack/spack/util/spack_yaml.py
+++ b/lib/spack/spack/util/spack_yaml.py
@@ -47,7 +47,7 @@ class syaml_str(str):
 
 
 class syaml_int(int):
-    __repr__ = str.__repr__
+    __repr__ = int.__repr__
 
 
 #: mapping from syaml type -> primitive type