diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 5dee3b571..9a7eb1f44 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -329,6 +329,9 @@ endif(UNIX)
 export_to_parent_intermediate()
 if (DEFINED LWS_PLAT_UNIX)
 	set(LWS_PLAT_UNIX ${LWS_PLAT_UNIX} PARENT_SCOPE)
+	if (ILLUMOS)
+		add_definitions("-D__illumos__")
+	endif()
 endif()
 set(LWS_HAVE_MBEDTLS_NET_SOCKETS ${LWS_HAVE_MBEDTLS_NET_SOCKETS} PARENT_SCOPE)
 set(TEST_SERVER_SSL_KEY "${TEST_SERVER_SSL_KEY}" PARENT_SCOPE)
diff --git a/lib/core/context.c b/lib/core/context.c
index 66636022a..6f1b78682 100644
--- a/lib/core/context.c
+++ b/lib/core/context.c
@@ -30,7 +30,7 @@
 
 static const char *library_version = LWS_LIBRARY_VERSION;
 
-#if defined(__linux__)
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__illumos__)
 /* for setrlimit */
 #include <sys/resource.h>
 #endif
diff --git a/lib/plat/unix/CMakeLists.txt b/lib/plat/unix/CMakeLists.txt
index aa7b6ca46..efe52f398 100644
--- a/lib/plat/unix/CMakeLists.txt
+++ b/lib/plat/unix/CMakeLists.txt
@@ -37,7 +37,6 @@ execute_process( COMMAND grep -c illumos /lib/ld.so.1
 string(REGEX REPLACE "[\n]+" "" ILLUMOS "${ILLUMOS}")
 
 if (NOT ${ILLUMOS} MATCHES "0")
-	add_definitions( "-D__illumos__" )
 	set(ILLUMOS 1)
 endif()