diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6eec5a1..7b62e12 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -402,11 +402,12 @@ if(OPENUSD_HAS_CYCLES)
         DESTINATION bin/usd
         OPTIONAL
     )
-    # Cycles runtime deps (embree4, epoxy, imath, openvdb, OIDN, sycl, etc.)
+    # Cycles runtime deps (embree4, epoxy, imath, openvdb, OIDN, sycl, etc.).
+    # No OPTIONAL: install(DIRECTORY) disallows it with FILES_MATCHING, and the
+    # dir always exists here since it is produced by the CyclesBuild step.
     install(DIRECTORY "${CYCLES_INSTALL_DIR}/"
         DESTINATION bin
         FILES_MATCHING PATTERN "*.dll"
-        OPTIONAL
     )
     # tbb12.dll (used by openvdb/embree4) lives in the precompiled lib tree, not install output
     install(FILES "${CYCLES_TBB12_DLL}"