diff --git a/format.cc b/format.cc
index faeeaf79..ee4c9aea 100644
--- a/format.cc
+++ b/format.cc
@@ -41,6 +41,7 @@
 
 using std::size_t;
 using fmt::Formatter;
+using fmt::FormatSpec;
 
 #if _MSC_VER
 # undef snprintf