diff --git a/tools/mtmd/clip.cpp b/tools/mtmd/clip.cpp
index 1414f6ba4..3ae1f025e 100644
--- a/tools/mtmd/clip.cpp
+++ b/tools/mtmd/clip.cpp
@@ -29,6 +29,7 @@
 #include <limits>
 #include <array>
 #include <numeric>
+#include <functional>
 
 struct clip_logger_state g_logger_state = {GGML_LOG_LEVEL_CONT, clip_log_callback_default, NULL};