diff --git a/fpdfsdk/cpdfsdk_actionhandler.cpp b/fpdfsdk/cpdfsdk_actionhandler.cpp
index 9f4d2fb..bbca1bc 100644
--- a/fpdfsdk/cpdfsdk_actionhandler.cpp
+++ b/fpdfsdk/cpdfsdk_actionhandler.cpp
@@ -17,8 +17,8 @@
 #include "fxjs/ijs_event_context.h"
 #include "fxjs/ijs_runtime.h"
 #include "third_party/base/check.h"
+#include "third_party/base/containers/contains.h"
 #include "third_party/base/notreached.h"
-#include "third_party/base/stl_util.h"
 
 bool CPDFSDK_ActionHandler::DoAction_DocOpen(
     const CPDF_Action& action,
diff --git a/fpdfsdk/cpdfsdk_annotiterator.cpp b/fpdfsdk/cpdfsdk_annotiterator.cpp
index 723665f..1c20f4c 100644
--- a/fpdfsdk/cpdfsdk_annotiterator.cpp
+++ b/fpdfsdk/cpdfsdk_annotiterator.cpp
@@ -12,7 +12,7 @@
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
 #include "fpdfsdk/cpdfsdk_annot.h"
 #include "fpdfsdk/cpdfsdk_pageview.h"
-#include "third_party/base/stl_util.h"
+#include "third_party/base/containers/contains.h"
 
 namespace {
 
diff --git a/fpdfsdk/cpdfsdk_baannothandler.cpp b/fpdfsdk/cpdfsdk_baannothandler.cpp
index 6aee006..d0be736 100644
--- a/fpdfsdk/cpdfsdk_baannothandler.cpp
+++ b/fpdfsdk/cpdfsdk_baannothandler.cpp
@@ -21,7 +21,7 @@
 #include "fpdfsdk/formfiller/cffl_formfield.h"
 #include "public/fpdf_fwlevent.h"
 #include "third_party/base/check.h"
-#include "third_party/base/stl_util.h"
+#include "third_party/base/containers/contains.h"
 
 namespace {
 
diff --git a/fpdfsdk/cpdfsdk_pageview.cpp b/fpdfsdk/cpdfsdk_pageview.cpp
index 68aff81..83993c7 100644
--- a/fpdfsdk/cpdfsdk_pageview.cpp
+++ b/fpdfsdk/cpdfsdk_pageview.cpp
@@ -21,8 +21,8 @@
 #include "fpdfsdk/cpdfsdk_helpers.h"
 #include "fpdfsdk/cpdfsdk_interactiveform.h"
 #include "third_party/base/check.h"
+#include "third_party/base/containers/contains.h"
 #include "third_party/base/ptr_util.h"
-#include "third_party/base/stl_util.h"
 
 #ifdef PDF_ENABLE_XFA
 #include "fpdfsdk/fpdfxfa/cpdfxfa_page.h"
diff --git a/fpdfsdk/cpdfsdk_widgethandler.cpp b/fpdfsdk/cpdfsdk_widgethandler.cpp
index 90b6cef..8f4a7f0 100644
--- a/fpdfsdk/cpdfsdk_widgethandler.cpp
+++ b/fpdfsdk/cpdfsdk_widgethandler.cpp
@@ -21,7 +21,7 @@
 #include "fpdfsdk/formfiller/cffl_formfield.h"
 #include "third_party/base/check.h"
 #include "third_party/base/check_op.h"
-#include "third_party/base/stl_util.h"
+#include "third_party/base/containers/contains.h"
 
 CPDFSDK_WidgetHandler::CPDFSDK_WidgetHandler() = default;
 
diff --git a/fpdfsdk/formfiller/cffl_listbox.cpp b/fpdfsdk/formfiller/cffl_listbox.cpp
index 791d638..578c255 100644
--- a/fpdfsdk/formfiller/cffl_listbox.cpp
+++ b/fpdfsdk/formfiller/cffl_listbox.cpp
@@ -14,7 +14,7 @@
 #include "fpdfsdk/cpdfsdk_widget.h"
 #include "fpdfsdk/formfiller/cffl_interactiveformfiller.h"
 #include "fpdfsdk/pwl/cpwl_list_box.h"
-#include "third_party/base/stl_util.h"
+#include "third_party/base/containers/contains.h"
 
 CFFL_ListBox::CFFL_ListBox(CPDFSDK_FormFillEnvironment* pApp,
                            CPDFSDK_Widget* pWidget)
diff --git a/fpdfsdk/fpdf_annot_embeddertest.cpp b/fpdfsdk/fpdf_annot_embeddertest.cpp
index ceeb020..f77fef0 100644
--- a/fpdfsdk/fpdf_annot_embeddertest.cpp
+++ b/fpdfsdk/fpdf_annot_embeddertest.cpp
@@ -30,9 +30,9 @@
 #include "testing/gmock/include/gmock/gmock-matchers.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/utils/hash.h"
+#include "third_party/base/containers/contains.h"
 #include "third_party/base/cxx17_backports.h"
 #include "third_party/base/span.h"
-#include "third_party/base/stl_util.h"
 
 using pdfium::kAnnotationStampWithApChecksum;
 
diff --git a/fpdfsdk/fpdf_doc.cpp b/fpdfsdk/fpdf_doc.cpp
index 78e0f6d..3bed946 100644
--- a/fpdfsdk/fpdf_doc.cpp
+++ b/fpdfsdk/fpdf_doc.cpp
@@ -28,7 +28,7 @@
 #include "fpdfsdk/cpdfsdk_helpers.h"
 #include "public/fpdf_formfill.h"
 #include "third_party/base/check.h"
-#include "third_party/base/stl_util.h"
+#include "third_party/base/containers/contains.h"
 
 namespace {
 
diff --git a/fpdfsdk/fpdf_edittext.cpp b/fpdfsdk/fpdf_edittext.cpp
index 4c58e47..918c909 100644
--- a/fpdfsdk/fpdf_edittext.cpp
+++ b/fpdfsdk/fpdf_edittext.cpp
@@ -29,7 +29,7 @@
 #include "public/fpdf_edit.h"
 #include "third_party/base/check.h"
 #include "third_party/base/check_op.h"
-#include "third_party/base/stl_util.h"
+#include "third_party/base/containers/contains.h"
 
 // These checks are here because core/ and public/ cannot depend on each other.
 static_assert(static_cast<int>(TextRenderingMode::MODE_UNKNOWN) ==
diff --git a/fpdfsdk/pwl/cpwl_wnd.cpp b/fpdfsdk/pwl/cpwl_wnd.cpp
index ed0b4af..2a3dbd4 100644
--- a/fpdfsdk/pwl/cpwl_wnd.cpp
+++ b/fpdfsdk/pwl/cpwl_wnd.cpp
@@ -16,6 +16,7 @@
 #include "public/fpdf_fwlevent.h"
 #include "third_party/base/check.h"
 #include "third_party/base/check_op.h"
+#include "third_party/base/containers/contains.h"
 #include "third_party/base/stl_util.h"
 
 namespace {