diff --git a/repos/base-sel4/patches/root_cnode.patch b/repos/base-sel4/patches/root_cnode.patch
new file mode 100644
index 0000000000..e3229038e6
--- /dev/null
+++ b/repos/base-sel4/patches/root_cnode.patch
@@ -0,0 +1,11 @@
+--- src/kernel/sel4/include/plat/pc99/autoconf.h
++++ src/kernel/sel4/include/plat/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 12
++#define CONFIG_ROOT_CNODE_SIZE_BITS 15
+ #define CONFIG_NUM_PRIORITIES 256
+ #define CONFIG_TESTPRINTER_REGEX ".*"
+ #define CONFIG_APP_SEL4TEST 1
diff --git a/repos/base-sel4/ports/sel4.hash b/repos/base-sel4/ports/sel4.hash
index 0b780e9759..bb88136d80 100644
--- a/repos/base-sel4/ports/sel4.hash
+++ b/repos/base-sel4/ports/sel4.hash
@@ -1 +1 @@
-805dca7fb390b8803114548e3c3175fced0c4d58
+4a35ff120456dea8de73ace7d9af53ace91da540
diff --git a/repos/base-sel4/src/core/include/core_cspace.h b/repos/base-sel4/src/core/include/core_cspace.h
index f9aee66f13..5de78bc2ba 100644
--- a/repos/base-sel4/src/core/include/core_cspace.h
+++ b/repos/base-sel4/src/core/include/core_cspace.h
@@ -26,7 +26,8 @@ class Genode::Core_cspace
 		/* CNode dimensions */
 		enum {
 			NUM_TOP_SEL_LOG2  = 12UL,
-			NUM_CORE_SEL_LOG2 = 14UL,
+			/* CONFIG_ROOT_CNODE_SIZE_BITS from seL4 autoconf.h */
+			NUM_CORE_SEL_LOG2 = CONFIG_ROOT_CNODE_SIZE_BITS + 1,
 			NUM_PHYS_SEL_LOG2 = 20UL,
 
 			NUM_CORE_PAD_SEL_LOG2 = 32UL - NUM_TOP_SEL_LOG2 - NUM_CORE_SEL_LOG2,
@@ -53,5 +54,4 @@ class Genode::Core_cspace
 		enum { CORE_VM_ID = 1 };
 };
 
-
 #endif /* _CORE__INCLUDE__CORE_CSPACE_H_ */