diff --git a/tests/modsys/functors/T017.cry b/tests/modsys/functors/T017.cry
new file mode 100644
index 00000000..0dbd2fde
--- /dev/null
+++ b/tests/modsys/functors/T017.cry
@@ -0,0 +1 @@
+module T017 = T017_F { T017_M }
diff --git a/tests/modsys/functors/T017.icry b/tests/modsys/functors/T017.icry
new file mode 100644
index 00000000..20ee0a7e
--- /dev/null
+++ b/tests/modsys/functors/T017.icry
@@ -0,0 +1,2 @@
+:load T017.cry
+y
diff --git a/tests/modsys/functors/T017.icry.stdout b/tests/modsys/functors/T017.icry.stdout
new file mode 100644
index 00000000..04784e24
--- /dev/null
+++ b/tests/modsys/functors/T017.icry.stdout
@@ -0,0 +1,7 @@
+Loading module Cryptol
+Loading module Cryptol
+Loading interface module T017_F$interface
+Loading module T017_F
+Loading module T017_M
+Loading module T017
+0x04
diff --git a/tests/modsys/functors/T017_F.cry b/tests/modsys/functors/T017_F.cry
new file mode 100644
index 00000000..aebca445
--- /dev/null
+++ b/tests/modsys/functors/T017_F.cry
@@ -0,0 +1,6 @@
+module T017_F where
+
+parameter
+  x : [8]
+
+y = x + x
diff --git a/tests/modsys/functors/T017_M.cry b/tests/modsys/functors/T017_M.cry
new file mode 100644
index 00000000..e8a0970c
--- /dev/null
+++ b/tests/modsys/functors/T017_M.cry
@@ -0,0 +1,4 @@
+module T017_M where
+
+x : [8]
+x = 2