diff --git a/BUILD.gn b/BUILD.gn
index 1e44a857..7d2f0a12 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -16,6 +16,11 @@ import("build/crashpad_buildconfig.gni")
 import("build/test.gni")
 import("util/net/tls.gni")
 
+if (crashpad_is_in_chromium) {
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
+}
+
 config("crashpad_config") {
   include_dirs = [ "." ]
 }
diff --git a/build/crashpad_buildconfig.gni b/build/crashpad_buildconfig.gni
index 7540fb28..d919a8b4 100644
--- a/build/crashpad_buildconfig.gni
+++ b/build/crashpad_buildconfig.gni
@@ -51,8 +51,8 @@ if (crashpad_is_in_chromium) {
     import("../../../mini_chromium/mini_chromium/build/compiler.gni")
     import("../../../mini_chromium/mini_chromium/build/platform.gni")
   } else {
-    # Both standalone and in Fuchsia tree use mini_chromium, and it's mapped into
-    # the same location in both cases.
+    # Both standalone and in Fuchsia tree use mini_chromium, and it's mapped
+    # into the same location in both cases.
     import("../third_party/mini_chromium/mini_chromium/build/compiler.gni")
     import("../third_party/mini_chromium/mini_chromium/build/platform.gni")
   }
diff --git a/client/BUILD.gn b/client/BUILD.gn
index 32b47fd5..a74ddc3f 100644
--- a/client/BUILD.gn
+++ b/client/BUILD.gn
@@ -14,6 +14,11 @@
 
 import("../build/crashpad_buildconfig.gni")
 
+if (crashpad_is_in_chromium) {
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
+}
+
 static_library("client") {
   sources = [
     "annotation.cc",
@@ -51,7 +56,6 @@ static_library("client") {
   }
 
   if (crashpad_is_linux || crashpad_is_android) {
-    set_sources_assignment_filter([])
     sources += [
       "crashpad_client_linux.cc",
       "simulate_crash_linux.h",
diff --git a/compat/BUILD.gn b/compat/BUILD.gn
index 9c22acfc..ba9d78cd 100644
--- a/compat/BUILD.gn
+++ b/compat/BUILD.gn
@@ -14,6 +14,11 @@
 
 import("../build/crashpad_buildconfig.gni")
 
+if (crashpad_is_in_chromium) {
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
+}
+
 config("compat_config") {
   include_dirs = []
 
diff --git a/handler/BUILD.gn b/handler/BUILD.gn
index 51ff2cf2..472c1477 100644
--- a/handler/BUILD.gn
+++ b/handler/BUILD.gn
@@ -14,6 +14,11 @@
 
 import("../build/crashpad_buildconfig.gni")
 
+if (crashpad_is_in_chromium) {
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
+}
+
 static_library("handler") {
   sources = [
     "crash_report_upload_thread.cc",
@@ -40,7 +45,6 @@ static_library("handler") {
   }
 
   if (crashpad_is_linux || crashpad_is_android) {
-    set_sources_assignment_filter([])
     sources += [
       "linux/capture_snapshot.cc",
       "linux/capture_snapshot.h",
@@ -169,7 +173,6 @@ if (crashpad_is_android) {
   }
 
   crashpad_executable("crashpad_handler_trampoline") {
-    set_sources_assignment_filter([])
     output_name = "libcrashpad_handler_trampoline.so"
 
     sources = [ "linux/handler_trampoline.cc" ]
diff --git a/minidump/BUILD.gn b/minidump/BUILD.gn
index 88227646..804f39f7 100644
--- a/minidump/BUILD.gn
+++ b/minidump/BUILD.gn
@@ -14,6 +14,11 @@
 
 import("../build/crashpad_buildconfig.gni")
 
+if (crashpad_is_in_chromium) {
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
+}
+
 static_library("minidump") {
   sources = [
     "minidump_annotation_writer.cc",
diff --git a/test/BUILD.gn b/test/BUILD.gn
index 7b052f0a..69ba5b44 100644
--- a/test/BUILD.gn
+++ b/test/BUILD.gn
@@ -14,6 +14,11 @@
 
 import("../build/crashpad_buildconfig.gni")
 
+if (crashpad_is_in_chromium) {
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
+}
+
 static_library("test") {
   testonly = true
 
@@ -84,7 +89,6 @@ static_library("test") {
   }
 
   if (crashpad_is_linux || crashpad_is_android) {
-    set_sources_assignment_filter([])
     sources += [
       "linux/fake_ptrace_connection.cc",
       "linux/fake_ptrace_connection.h",
diff --git a/test/ios/BUILD.gn b/test/ios/BUILD.gn
index 59dd35d5..cbf8ef89 100644
--- a/test/ios/BUILD.gn
+++ b/test/ios/BUILD.gn
@@ -16,6 +16,9 @@ import("../../build/crashpad_buildconfig.gni")
 
 if (crashpad_is_in_chromium) {
   import("//build/config/ios/rules.gni")
+
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
 } else if (crashpad_is_standalone) {
   import("//third_party/mini_chromium/mini_chromium/build/ios/rules.gni")
 }
diff --git a/test/ios/host/BUILD.gn b/test/ios/host/BUILD.gn
index 20f25003..0a14f179 100644
--- a/test/ios/host/BUILD.gn
+++ b/test/ios/host/BUILD.gn
@@ -16,6 +16,9 @@ import("../../../build/crashpad_buildconfig.gni")
 
 if (crashpad_is_in_chromium) {
   import("//build/config/ios/rules.gni")
+
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
 } else if (crashpad_is_standalone) {
   import("//third_party/mini_chromium/mini_chromium/build/ios/rules.gni")
 }
diff --git a/tools/BUILD.gn b/tools/BUILD.gn
index 7da109bc..592e0ad5 100644
--- a/tools/BUILD.gn
+++ b/tools/BUILD.gn
@@ -14,6 +14,11 @@
 
 import("../build/crashpad_buildconfig.gni")
 
+if (crashpad_is_in_chromium) {
+  # Prevent Chromium source assignment filters from being inherited.
+  set_sources_assignment_filter([])
+}
+
 source_set("tool_support") {
   sources = [
     "tool_support.cc",