diff --git a/.gitmodules b/.gitmodules
index efa14ef..2547906 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -20,6 +20,9 @@
 [submodule "submodules/gem5"]
 	path = submodules/gem5
 	url = https://github.com/cirosantilli/gem5
+[submodule "submodules/gensim-simulator"]
+	path = submodules/gensim-simulator
+	url = https://github.com/cirosantilli/gensim-simulator
 [submodule "submodules/glibc"]
 	path = submodules/glibc
 	url = https://github.com/cirosantilli/glibc
diff --git a/README.adoc b/README.adoc
index 42fea47..dbea908 100644
--- a/README.adoc
+++ b/README.adoc
@@ -18267,6 +18267,7 @@ TODO: advantages over QEMU. Like the name implies, they seem to have a nice ISA
 Build on Ubuntu 20.04:
 
 ....
+git submodule update --init submodules/gensim-simulator
 sudo apt install libantlr3c-dev
 cd submodule/gensim
 make
diff --git a/submodules/gensim-simulator b/submodules/gensim-simulator
new file mode 160000
index 0000000..d781121
--- /dev/null
+++ b/submodules/gensim-simulator
@@ -0,0 +1 @@
+Subproject commit d78112156d8903faa6f3697b9fbdccde0d294131