diff --git a/third_party/agg23/agg_array.h b/third_party/agg23/agg_array.h
index b82d95296..ed22c40e9 100644
--- a/third_party/agg23/agg_array.h
+++ b/third_party/agg23/agg_array.h
@@ -16,6 +16,8 @@
 #ifndef AGG_ARRAY_INCLUDED
 #define AGG_ARRAY_INCLUDED
 
+#include <string.h>
+
 #include "agg_basics.h"
 #include "core/fxcrt/fx_memory.h"  // For FXSYS_* macros.
 
diff --git a/third_party/agg23/agg_path_storage.cpp b/third_party/agg23/agg_path_storage.cpp
index 2981e9c0c..d4225124d 100644
--- a/third_party/agg23/agg_path_storage.cpp
+++ b/third_party/agg23/agg_path_storage.cpp
@@ -25,6 +25,8 @@
 
 #include "agg_path_storage.h"
 
+#include <string.h>
+
 #include "agg_math.h"
 #include "core/fxcrt/fx_memory.h"