diff --git a/.gitmodules b/.gitmodules
index 60d54b45eb0..7f069abd3d3 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -35,3 +35,6 @@
 [submodule "CryptoPkg/Library/MbedTlsLib/mbedtls"]
 	path = CryptoPkg/Library/MbedTlsLib/mbedtls
 	url = https://github.com/ARMmbed/mbedtls
+[submodule "SecurityPkg/DeviceSecurity/SpdmLib/libspdm"]
+	path = SecurityPkg/DeviceSecurity/SpdmLib/libspdm
+	url = https://github.com/DMTF/libspdm.git