diff --git a/scripts/check_test_coverage.sh b/scripts/check_test_coverage.sh
new file mode 100755
index 0000000..e5f4a35
--- /dev/null
+++ b/scripts/check_test_coverage.sh
@@ -0,0 +1,36 @@
+#!/bin/bash
+
+if [ ! -d spec ]
+then
+	echo "Error: spec folder not found"
+	echo "       run this script from the root of repo"
+	exit 1
+fi
+
+function missing_unit_tests() {
+	local ruby_file
+	local got_err=0
+	while read -r ruby_file
+	do
+		ruby_file="${ruby_file::-3}"
+		if ! grep -rq "$ruby_file" spec/
+		then
+			echo "[-] Error: missing unit tests for $ruby_file.rb"
+			got_err=1
+		fi
+	done < <(find lib/ -name "*.rb")
+	if [ "$got_err" == "0" ]
+	then
+		echo "[+] OK: every file has a unit test."
+		return 1
+	else
+		echo "[-] Error: missing unit tests."
+		return 0
+	fi
+}
+
+if missing_unit_tests
+then
+	exit 1
+fi
+