diff --git a/go.mod b/go.mod
index 6aba6839..c7ff71ba 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module bitbucket.org/ausocean/av
 
-go 1.17
+go 1.16
 
 require (
 	bitbucket.org/ausocean/iot v1.3.0
diff --git a/turbidity/main.go b/turbidity/main.go
index fedc49b3..5ea8847c 100644
--- a/turbidity/main.go
+++ b/turbidity/main.go
@@ -1,3 +1,5 @@
+// +build !nocv
+
 package main
 
 import (
diff --git a/turbidity/results.go b/turbidity/results.go
index 4dc24b52..7a2fd3fd 100644
--- a/turbidity/results.go
+++ b/turbidity/results.go
@@ -1,3 +1,5 @@
+// +build !nocv
+
 package main
 
 // struct to hold the results of the turbidity sensor.
diff --git a/turbidity/turbidity.go b/turbidity/turbidity.go
index c065eef6..7deca9cc 100644
--- a/turbidity/turbidity.go
+++ b/turbidity/turbidity.go
@@ -1,3 +1,5 @@
+// +build !nocv
+
 package main
 
 import (