diff --git a/lib/spack/spack/util/url.py b/lib/spack/spack/util/url.py
index 4d511c29d22..81443aed5c2 100644
--- a/lib/spack/spack/util/url.py
+++ b/lib/spack/spack/util/url.py
@@ -343,7 +343,7 @@ def parse_git_url(url):
 
 
 def require_url_format(url):
-    ut = re.search(r'^(file://|http://|https://|ftp://|s3://|gs://|/)', url)
+    ut = re.search(r'^(file://|http://|https://|ftp://|s3://|gs://|ssh://|/)', url)
     assert ut is not None