diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index 50161db563b..cf5c56f31a7 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -152,7 +152,7 @@
     r"(})?"  # finish format string with non-escaped close brace }, or missing if not present
     r"|"
     # OPTION 3: mismatched close brace (option 2 would consume a matched open brace)
-    r"(})" r")",  # brace
+    r"(})"  # brace
     r")",
     re.IGNORECASE,
 )