diff --git a/src/app/core/labeling.cc b/src/app/core/labeling.cc
index 7db27a01..b8b4be4e 100644
--- a/src/app/core/labeling.cc
+++ b/src/app/core/labeling.cc
@@ -7,6 +7,7 @@
 #include <unordered_map>
 #include <vector>
 
+#include "absl/strings/str_format.h"
 #include "app/core/common.h"
 #include "app/core/constants.h"
 #include "app/gui/icons.h"