diff --git a/BUILD.bazel b/BUILD.bazel
index 1721c68a7..088646b22 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -143,6 +143,7 @@ cc_library(
         "src/lib/IlmThread/IlmThreadMutex.h",
         "src/lib/IlmThread/IlmThreadNamespace.h",
         "src/lib/IlmThread/IlmThreadPool.h",
+        "src/lib/IlmThread/IlmThreadProcessGroup.h",
         "src/lib/IlmThread/IlmThreadSemaphore.h",
     ],
     copts = select({