diff --git a/.gitmodules b/.gitmodules
index df0ce20..efb36a8 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,3 +7,6 @@
 [submodule "third_party/becrypto"]
 	path = third_party/becrypto
 	url = git@git.kingsome.cn:crypto/becrypto.git
+[submodule "third_party/contracts-imtbl"]
+	path = third_party/contracts-imtbl
+	url = git@git.kingsome.cn:crypto/contracts-imtbl.git
diff --git a/third_party/contracts-imtbl b/third_party/contracts-imtbl
new file mode 160000
index 0000000..0cb0cad
--- /dev/null
+++ b/third_party/contracts-imtbl
@@ -0,0 +1 @@
+Subproject commit 0cb0cadc67f36cc524b534860d268c38fc1dbbde