diff --git a/internal/addrs/module_call.go b/internal/addrs/module_call.go
index d80b35a589..4e8ce34f2b 100644
--- a/internal/addrs/module_call.go
+++ b/internal/addrs/module_call.go
@@ -70,6 +70,14 @@ func (c AbsModuleCall) Instance(key InstanceKey) ModuleInstance {
 	return ret
 }
 
+type absModuleCallInstanceKey string
+
+func (c AbsModuleCall) UniqueKey() UniqueKey {
+	return absModuleCallInstanceKey(c.String())
+}
+
+func (mk absModuleCallInstanceKey) uniqueKeySigil() {}
+
 // ModuleCallInstance is the address of one instance of a module created from
 // a module call, which might create multiple instances using "count" or
 // "for_each" arguments.
diff --git a/internal/addrs/moveable.go b/internal/addrs/moveable.go
index fd93b58dca..a85fe72c1c 100644
--- a/internal/addrs/moveable.go
+++ b/internal/addrs/moveable.go
@@ -11,6 +11,7 @@ package addrs
 // the current module where the address is defined. The type MoveEndpoint
 type AbsMoveable interface {
 	absMoveableSigil()
+	UniqueKeyer
 
 	String() string
 }
diff --git a/internal/addrs/resource.go b/internal/addrs/resource.go
index a7b7ee308d..a26f941c94 100644
--- a/internal/addrs/resource.go
+++ b/internal/addrs/resource.go
@@ -194,6 +194,14 @@ func (r AbsResource) absMoveableSigil() {
 	// AbsResource is moveable
 }
 
+type absResourceKey string
+
+func (r AbsResource) UniqueKey() UniqueKey {
+	return absResourceInstanceKey(r.String())
+}
+
+func (rk absResourceKey) uniqueKeySigil() {}
+
 // AbsResourceInstance is an absolute address for a resource instance under a
 // given module path.
 type AbsResourceInstance struct {