diff --git a/var/spack/repos/builtin/packages/r-ptw/package.py b/var/spack/repos/builtin/packages/r-ptw/package.py
index 484db59ebb6..9636b56db51 100644
--- a/var/spack/repos/builtin/packages/r-ptw/package.py
+++ b/var/spack/repos/builtin/packages/r-ptw/package.py
@@ -31,5 +31,6 @@ class RPtw(RPackage):
 
     depends_on("c", type="build")  # generated
 
-    depends_on("r-nloptr", type=("build", "run"))
     depends_on("r-rcppde", type=("build", "run"), when="@1.9-16:")
+
+    depends_on("r-nloptr", type=("build", "run"), when="@:1.9-15")