diff --git a/src/lib/math/pcurves/pcurves_id.h b/src/lib/math/pcurves/pcurves_id.h
index 915dd95..3d39666 100644
--- a/src/lib/math/pcurves/pcurves_id.h
+++ b/src/lib/math/pcurves/pcurves_id.h
@@ -10,6 +10,7 @@
 #include <botan/secmem.h>
 #include <botan/types.h>
 #include <optional>
+#include <string>
 #include <string_view>
 #include <vector>