diff --git a/lib/spack/spack/solver/asp.py b/lib/spack/spack/solver/asp.py
index b9cb8d0a1fd..625d0aa5671 100644
--- a/lib/spack/spack/solver/asp.py
+++ b/lib/spack/spack/solver/asp.py
@@ -1933,7 +1933,7 @@ class Head:
             node_compiler_version = fn.attr("node_compiler_version_set")
             node_flag = fn.attr("node_flag_set")
             node_flag_source = fn.attr("node_flag_source")
-            node_flag_propagation_candidate= fn.attr("node_flag_propagation_candidate")
+            node_flag_propagation_candidate = fn.attr("node_flag_propagation_candidate")
             variant_propagation_candidate = fn.attr("variant_propagation_candidate")
 
         class Body:
@@ -1947,7 +1947,7 @@ class Body:
             node_compiler_version = fn.attr("node_compiler_version")
             node_flag = fn.attr("node_flag")
             node_flag_source = fn.attr("node_flag_source")
-            node_flag_propagation_candidate= fn.attr("node_flag_propagation_candidate")
+            node_flag_propagation_candidate = fn.attr("node_flag_propagation_candidate")
             variant_propagation_candidate = fn.attr("variant_propagation_candidate")
 
         f = Body if body else Head