diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index 7d3014a71d..522485f57e 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -2789,11 +2789,11 @@ def inject_patches_variant(root):
         # Also record all patches required on dependencies by
         # depends_on(..., patch=...)
         for dspec in root.traverse_edges(deptype=all, cover="edges", root=False):
-            pkg_deps = dspec.parent.package_class.dependencies
-            if dspec.spec.name not in pkg_deps:
+            if dspec.spec.concrete:
                 continue
 
-            if dspec.spec.concrete:
+            pkg_deps = dspec.parent.package_class.dependencies
+            if dspec.spec.name not in pkg_deps:
                 continue
 
             patches = []