diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 40887b6aa..7a1b31d0f 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -11,6 +11,7 @@
 #include <atomic>
 #include <limits>
 #include <map>
+#include <unordered_map>
 #include <unordered_set>
 #include <memory>
 #include <string>