diff --git a/core/fpdfapi/edit/cpdf_contentstream_write_utils.cpp b/core/fpdfapi/edit/cpdf_contentstream_write_utils.cpp
index 28165b1..612303d 100644
--- a/core/fpdfapi/edit/cpdf_contentstream_write_utils.cpp
+++ b/core/fpdfapi/edit/cpdf_contentstream_write_utils.cpp
@@ -4,6 +4,8 @@
 
 #include "core/fpdfapi/edit/cpdf_contentstream_write_utils.h"
 
+#include <ostream>
+
 #include "third_party/skia_shared/SkFloatToDecimal.h"
 
 std::ostream& WriteFloat(std::ostream& stream, float value) {
diff --git a/core/fpdfapi/edit/cpdf_contentstream_write_utils.h b/core/fpdfapi/edit/cpdf_contentstream_write_utils.h
index 3e14c9f..c94e99e 100644
--- a/core/fpdfapi/edit/cpdf_contentstream_write_utils.h
+++ b/core/fpdfapi/edit/cpdf_contentstream_write_utils.h
@@ -5,7 +5,7 @@
 #ifndef CORE_FPDFAPI_EDIT_CPDF_CONTENTSTREAM_WRITE_UTILS_H_
 #define CORE_FPDFAPI_EDIT_CPDF_CONTENTSTREAM_WRITE_UTILS_H_
 
-#include <ostream>
+#include <iosfwd>
 
 #include "core/fxcrt/fx_coordinates.h"
 
diff --git a/core/fpdfapi/edit/cpdf_stringarchivestream.cpp b/core/fpdfapi/edit/cpdf_stringarchivestream.cpp
index 492fb2a..9cb1336 100644
--- a/core/fpdfapi/edit/cpdf_stringarchivestream.cpp
+++ b/core/fpdfapi/edit/cpdf_stringarchivestream.cpp
@@ -4,6 +4,8 @@
 
 #include "core/fpdfapi/edit/cpdf_stringarchivestream.h"
 
+#include <sstream>
+
 #include "third_party/base/notreached.h"
 
 CPDF_StringArchiveStream::CPDF_StringArchiveStream(std::ostringstream* stream)