diff --git a/7seg.cpp b/7seg.cpp
index 57a18fd..4c9f273 100644
--- a/7seg.cpp
+++ b/7seg.cpp
@@ -24,8 +24,9 @@
 
 namespace fs = std::experimental::filesystem;
 
-static void DisplayDbusValue(uint64_t postcode)
+static void DisplayDbusValue(postcode_t postcodes)
 {
+    auto postcode = std::get<primary_post_code_t>(postcodes);
     // Uses cstdio instead of streams because the device file has
     // very strict requirements about the data format and streaming
     // abstractions tend to muck it up.