diff --git a/src/format.hpp b/src/format.hpp
index cbece27..8fa6dc8 100644
--- a/src/format.hpp
+++ b/src/format.hpp
@@ -49,6 +49,11 @@
     static constexpr auto format = "=%lld";
 };
 template <>
+struct GetFormatType<double>
+{
+    static constexpr auto format = "=%lf";
+};
+template <>
 struct GetFormatType<unsigned char>
 {
     static constexpr auto format = "=%hhd";