diff --git a/fpdfsdk/cpdfsdk_formfillenvironment.cpp b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
index c9bb7c9..155fcc0 100644
--- a/fpdfsdk/cpdfsdk_formfillenvironment.cpp
+++ b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
@@ -10,6 +10,7 @@
 #include <utility>
 
 #include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "core/fpdfdoc/cpdf_docjsactions.h"
 #include "fpdfsdk/cpdfsdk_actionhandler.h"
 #include "fpdfsdk/cpdfsdk_annothandlermgr.h"