diff --git a/ckb_consts.h b/ckb_consts.h
index 1fe421e..f166b2e 100644
--- a/ckb_consts.h
+++ b/ckb_consts.h
@@ -22,6 +22,7 @@
 #define SYS_ckb_spawn 2101
 #define SYS_ckb_get_memory_limit 2102
 #define SYS_ckb_set_content 2103
+#define SYS_ckb_load_extension 2104
 #define SYS_ckb_current_memory 2105
 
 #define CKB_SUCCESS 0
diff --git a/ckb_syscalls.h b/ckb_syscalls.h
index 8eaaedc..183fc1d 100644
--- a/ckb_syscalls.h
+++ b/ckb_syscalls.h
@@ -406,6 +406,11 @@ int ckb_current_memory() {
   return syscall(SYS_ckb_current_memory, 0, 0, 0, 0, 0, 0);
 }
 
+int ckb_load_extension(void* addr, uint64_t* len, size_t offset, size_t index, size_t source)
+{
+  return syscall(SYS_ckb_load_extension, addr, len, offset, index, source, 0);
+}
+
 #endif /* CKB_STDLIB_NO_SYSCALL_IMPL */
 
 #endif /* CKB_C_STDLIB_CKB_SYSCALLS_H_ */