--- src/kernel/sel4/configs/pc99/autoconf.h
+++ src/kernel/sel4/configs/pc99/autoconf.h
@@ -77,7 +77,7 @@
 #define CONFIG_USER_OPTIMISATION_O2 1
 #define CONFIG_LIB_CPIO 1
 #define CONFIG_RETYPE_FAN_OUT_LIMIT 256
-#define CONFIG_ROOT_CNODE_SIZE_BITS 16
+#define CONFIG_ROOT_CNODE_SIZE_BITS 18
 #define CONFIG_NUM_PRIORITIES 256
 #define CONFIG_TESTPRINTER_REGEX ".*"
 #define CONFIG_APP_SEL4TEST 1
