diff --git a/src/builder.h b/src/builder.h
index f6913cd1..27d5a06f 100644
--- a/src/builder.h
+++ b/src/builder.h
@@ -49,24 +49,10 @@ class Builder {
   // Adds a string to the profile string table if not already present.
   // Returns a unique integer id for this string.
   int64_t StringId(absl::string_view str);
-  [[deprecated("Use absl::string_view instead.")]] ABSL_REFACTOR_INLINE int64_t
-  StringId(const char* str) {
-    return StringId(absl::NullSafeStringView(str));
+  [[deprecated("Use StringId instead.")]] ABSL_REFACTOR_INLINE int64_t
+  StringIdForMigration(absl::string_view str) {
+    return StringId(str);
   }
-#if ABSL_HAVE_ATTRIBUTE(enable_if)
-  [[deprecated("Use absl::string_view instead.")]] ABSL_REFACTOR_INLINE int64_t
-  StringId(const char* str) __attribute__((enable_if(str != nullptr, ""))) {
-    return StringIdForMigration(str);
-  }
-#endif
-  // This overload is only for migration. It allows us to avoid
-  // `absl::NullSafeStringView` for strings we can statically prove are not
-  // null.
-  //
-  // This will be marked for inlining once all callers of
-  // `StringId(const char*)` are migrated. Before then, we may run into inlining
-  // cycles or less-than-readable inlining.
-  int64_t StringIdForMigration(absl::string_view str) { return StringId(str); }
 
   // Adds a function with these attributes to the profile function
   // table, if not already present. Returns a unique integer id for
diff --git a/src/perf_data_handler_test.cc b/src/perf_data_handler_test.cc
index ddb9f65e..37a9dde5 100644
--- a/src/perf_data_handler_test.cc
+++ b/src/perf_data_handler_test.cc
@@ -170,8 +170,7 @@ class TestPerfDataHandler : public PerfDataHandler {
  private:
   // Ensure necessary information contained in the BranchStackEntry is also
   // present in the resulting profile.
-  inline void CheckBranchEquality(BranchStackEntry expected,
-                                  BranchStackPair actual) {
+  void CheckBranchEquality(BranchStackEntry expected, BranchStackPair actual) {
     EXPECT_EQ(expected.from_ip(), actual.from.ip);
     EXPECT_EQ(expected.to_ip(), actual.to.ip);
     EXPECT_EQ(expected.mispredicted(), actual.mispredicted);
diff --git a/src/quipper/BUILD b/src/quipper/BUILD
index f76d54b8..3cdde04d 100644
--- a/src/quipper/BUILD
+++ b/src/quipper/BUILD
@@ -242,15 +242,20 @@ cc_library(
     hdrs = ["address_context.h"],
     visibility = ["//src:__subpackages__"],
     deps = [
+        ":compat",
         ":kernel",
-        ":perf_data_cc_proto",
     ],
 )
 
 cc_library(
     name = "address_mapper",
     srcs = ["address_mapper.cc"],
-    hdrs = ["address_mapper.h"],
+    hdrs = [
+        "address_mapper.h",
+        "compat/check.h",
+        "compat/non_cros/detail/check.h",
+    ],
+    includes = ["compat/non_cros"],
     deps = [
         ":base",
     ],
@@ -365,8 +370,8 @@ cc_library(
     visibility = ["//visibility:public"],
     deps = [
         ":binary_data_utils",
+        ":compat",
         ":kernel",
-        ":perf_data_cc_proto",
         ":base",
     ],
 )
diff --git a/src/quipper/address_context.cc b/src/quipper/address_context.cc
index 1bb9531f..d8865013 100644
--- a/src/quipper/address_context.cc
+++ b/src/quipper/address_context.cc
@@ -1,7 +1,7 @@
 #include "address_context.h"
 
+#include "compat/proto.h"
 #include "kernel/perf_event.h"
-#include "src/quipper/perf_data.pb.h"
 
 namespace quipper {
 
diff --git a/src/quipper/address_context.h b/src/quipper/address_context.h
index dafb1931..411436e9 100644
--- a/src/quipper/address_context.h
+++ b/src/quipper/address_context.h
@@ -1,8 +1,8 @@
 #ifndef PERF_DATA_CONVERTER_SRC_QUIPPER_ADDRESS_CONTEXT_H_
 #define PERF_DATA_CONVERTER_SRC_QUIPPER_ADDRESS_CONTEXT_H_
 
+#include "compat/proto.h"
 #include "kernel/perf_event.h"
-#include "src/quipper/perf_data.pb.h"
 
 namespace quipper {
 
diff --git a/src/quipper/address_mapper.h b/src/quipper/address_mapper.h
index ec4b6891..0958685e 100644
--- a/src/quipper/address_mapper.h
+++ b/src/quipper/address_mapper.h
@@ -11,7 +11,7 @@
 #include <list>
 #include <map>
 
-#include "base/logging.h"
+#include "compat/check.h"
 
 namespace quipper {
 
diff --git a/src/quipper/compat/check.h b/src/quipper/compat/check.h
new file mode 100644
index 00000000..b5f93ec5
--- /dev/null
+++ b/src/quipper/compat/check.h
@@ -0,0 +1,10 @@
+// Copyright 2026 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROMIUMOS_WIDE_PROFILING_COMPAT_CHECK_H_
+#define CHROMIUMOS_WIDE_PROFILING_COMPAT_CHECK_H_
+
+#include "detail/check.h"
+
+#endif  // CHROMIUMOS_WIDE_PROFILING_COMPAT_CHECK_H_
diff --git a/src/quipper/compat/cros/detail/check.h b/src/quipper/compat/cros/detail/check.h
new file mode 100644
index 00000000..7ffe6caf
--- /dev/null
+++ b/src/quipper/compat/cros/detail/check.h
@@ -0,0 +1,10 @@
+// Copyright 2026 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROMIUMOS_WIDE_PROFILING_COMPAT_CROS_DETAIL_CHECK_H_
+#define CHROMIUMOS_WIDE_PROFILING_COMPAT_CROS_DETAIL_CHECK_H_
+
+#include "base/check.h"
+
+#endif  // CHROMIUMOS_WIDE_PROFILING_COMPAT_CROS_DETAIL_CHECK_H_
diff --git a/src/quipper/compat/non_cros/detail/check.h b/src/quipper/compat/non_cros/detail/check.h
new file mode 100644
index 00000000..a6a0568d
--- /dev/null
+++ b/src/quipper/compat/non_cros/detail/check.h
@@ -0,0 +1,10 @@
+// Copyright 2026 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROMIUMOS_WIDE_PROFILING_COMPAT_EXT_DETAIL_CHECK_H_
+#define CHROMIUMOS_WIDE_PROFILING_COMPAT_EXT_DETAIL_CHECK_H_
+
+#include "base/logging.h"
+
+#endif  // CHROMIUMOS_WIDE_PROFILING_COMPAT_EXT_DETAIL_CHECK_H_
diff --git a/src/quipper/compat/proto.h b/src/quipper/compat/proto.h
index 118bf913..c2227048 100644
--- a/src/quipper/compat/proto.h
+++ b/src/quipper/compat/proto.h
@@ -5,7 +5,7 @@
 #ifndef CHROMIUMOS_WIDE_PROFILING_COMPAT_PROTO_H_
 #define CHROMIUMOS_WIDE_PROFILING_COMPAT_PROTO_H_
 
-#include "src/quipper/perf_data.pb.h"
+#include "perf_data.pb.h"
 #include "perf_parser_options.pb.h"
 #include "perf_stat.pb.h"
 #include "google/protobuf//arena.h"
diff --git a/src/quipper/perf_data_utils.cc b/src/quipper/perf_data_utils.cc
index 1a54767c..0e3a2a93 100644
--- a/src/quipper/perf_data_utils.cc
+++ b/src/quipper/perf_data_utils.cc
@@ -11,9 +11,9 @@
 #include <string>
 
 #include "base/logging.h"
+#include "compat/proto.h"
 #include "kernel/perf_event.h"
 #include "kernel/perf_internals.h"
-#include "src/quipper/perf_data.pb.h"
 
 namespace quipper {