diff --git a/.gitmodules b/.gitmodules
index fed995c693..7335f14796 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -728,3 +728,8 @@
 	url = ../outcome.git
 	fetchRecurseSubmodules = on-demand
 	branch = .
+[submodule "histogram"]
+	path = libs/histogram
+	url = ../histogram.git
+	fetchRecurseSubmodules = on-demand
+	branch = .
diff --git a/libs/histogram b/libs/histogram
new file mode 160000
index 0000000000..718952e589
--- /dev/null
+++ b/libs/histogram
@@ -0,0 +1 @@
+Subproject commit 718952e589ac3b6c9b16be218cd5fec34b2a5f3a