diff --git a/doc/fsl.utils.ensure.rst b/doc/fsl.utils.ensure.rst
new file mode 100644
index 0000000000000000000000000000000000000000..d8ab3ebada6612068dacf819d7e73207ab254ff8
--- /dev/null
+++ b/doc/fsl.utils.ensure.rst
@@ -0,0 +1,7 @@
+``fsl.utils.ensure``
+====================
+
+.. automodule:: fsl.utils.ensure
+    :members:
+    :undoc-members:
+    :show-inheritance:
diff --git a/doc/fsl.utils.rst b/doc/fsl.utils.rst
index 0f65ae3d63c3130cf456aab347a5b7a102cfd606..e64c6cbddb0852cc9ec00a57fc4978ebf92ae6d0 100644
--- a/doc/fsl.utils.rst
+++ b/doc/fsl.utils.rst
@@ -7,6 +7,7 @@
    fsl.utils.assertions
    fsl.utils.cache
    fsl.utils.callfsl
+   fsl.utils.ensure
    fsl.utils.idle
    fsl.utils.imcp
    fsl.utils.memoize