diff --git a/filesystem/filesystem.go b/filesystem/filesystem.go
index 61127bf16..cadf9c246 100644
--- a/filesystem/filesystem.go
+++ b/filesystem/filesystem.go
@@ -36,8 +36,8 @@ func init() {
 
 func registerBuildComponents(ctx android.RegistrationContext) {
 	ctx.RegisterModuleType("android_filesystem", filesystemFactory)
+	ctx.RegisterModuleType("android_filesystem_defaults", filesystemDefaultsFactory)
 	ctx.RegisterModuleType("android_system_image", systemImageFactory)
-	ctx.RegisterModuleType("android_system_image_defaults", systemImageDefaultsFactory)
 	ctx.RegisterModuleType("avb_add_hash_footer", avbAddHashFooterFactory)
 	ctx.RegisterModuleType("avb_add_hash_footer_defaults", avbAddHashFooterDefaultsFactory)
 	ctx.RegisterModuleType("avb_gen_vbmeta_image", avbGenVbmetaImageFactory)
@@ -47,6 +47,7 @@ func registerBuildComponents(ctx android.RegistrationContext) {
 type filesystem struct {
 	android.ModuleBase
 	android.PackagingBase
+	android.DefaultableModuleBase
 
 	properties filesystemProperties
 
@@ -144,6 +145,7 @@ func initFilesystemModule(module *filesystem) {
 	module.AddProperties(&module.properties)
 	android.InitPackageModule(module)
 	android.InitAndroidMultiTargetsArchModule(module, android.DeviceSupported, android.MultilibCommon)
+	android.InitDefaultableModule(module)
 }
 
 var dependencyTag = struct {
@@ -190,9 +192,7 @@ func (f *filesystem) partitionName() string {
 var pctx = android.NewPackageContext("android/soong/filesystem")
 
 func (f *filesystem) GenerateAndroidBuildActions(ctx android.ModuleContext) {
-	if !android.InList(f.PartitionType(), validPartitions) {
-		ctx.PropertyErrorf("partition_type", "partition_type must be one of %s, found: %s", validPartitions, f.PartitionType())
-	}
+	validatePartitionType(ctx, f)
 	switch f.fsType(ctx) {
 	case ext4Type:
 		f.output = f.buildImageUsingBuildImage(ctx)
@@ -208,6 +208,22 @@ func (f *filesystem) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	ctx.InstallFile(f.installDir, f.installFileName(), f.output)
 }
 
+func validatePartitionType(ctx android.ModuleContext, p partition) {
+	if !android.InList(p.PartitionType(), validPartitions) {
+		ctx.PropertyErrorf("partition_type", "partition_type must be one of %s, found: %s", validPartitions, p.PartitionType())
+	}
+
+	ctx.VisitDirectDepsWithTag(android.DefaultsDepTag, func(m android.Module) {
+		if fdm, ok := m.(*filesystemDefaults); ok {
+			if p.PartitionType() != fdm.PartitionType() {
+				ctx.PropertyErrorf("partition_type",
+					"%s doesn't match with the partition type %s of the filesystem default module %s",
+					p.PartitionType(), fdm.PartitionType(), m.Name())
+			}
+		}
+	})
+}
+
 // Copy extra files/dirs that are not from the `deps` property to `rootDir`, checking for conflicts with files
 // already in `rootDir`.
 func (f *filesystem) buildNonDepsFiles(ctx android.ModuleContext, builder *android.RuleBuilder, rootDir android.OutputPath) {
@@ -469,10 +485,16 @@ func (f *filesystem) addMakeBuiltFiles(ctx android.ModuleContext, builder *andro
 		Text(android.PathForArbitraryOutput(ctx, stagingDir).String())
 }
 
+type partition interface {
+	PartitionType() string
+}
+
 func (f *filesystem) PartitionType() string {
 	return proptools.StringDefault(f.properties.Partition_type, "system")
 }
 
+var _ partition = (*filesystem)(nil)
+
 var _ android.AndroidMkEntriesProvider = (*filesystem)(nil)
 
 // Implements android.AndroidMkEntriesProvider
@@ -546,3 +568,37 @@ var _ cc.UseCoverage = (*filesystem)(nil)
 func (*filesystem) IsNativeCoverageNeeded(ctx android.IncomingTransitionContext) bool {
 	return ctx.Device() && ctx.DeviceConfig().NativeCoverageEnabled()
 }
+
+// android_filesystem_defaults
+
+type filesystemDefaults struct {
+	android.ModuleBase
+	android.DefaultsModuleBase
+
+	properties filesystemDefaultsProperties
+}
+
+type filesystemDefaultsProperties struct {
+	// Identifies which partition this is for //visibility:any_system_image (and others) visibility
+	// checks, and will be used in the future for API surface checks.
+	Partition_type *string
+}
+
+// android_filesystem_defaults is a default module for android_filesystem and android_system_image
+func filesystemDefaultsFactory() android.Module {
+	module := &filesystemDefaults{}
+	module.AddProperties(&module.properties)
+	module.AddProperties(&android.PackagingProperties{})
+	android.InitDefaultsModule(module)
+	return module
+}
+
+func (f *filesystemDefaults) PartitionType() string {
+	return proptools.StringDefault(f.properties.Partition_type, "system")
+}
+
+var _ partition = (*filesystemDefaults)(nil)
+
+func (f *filesystemDefaults) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	validatePartitionType(ctx, f)
+}
diff --git a/filesystem/filesystem_test.go b/filesystem/filesystem_test.go
index 3ce5d4e88..f4ecad46c 100644
--- a/filesystem/filesystem_test.go
+++ b/filesystem/filesystem_test.go
@@ -381,7 +381,7 @@ func TestFileSystemWithCoverageVariants(t *testing.T) {
 
 func TestSystemImageDefaults(t *testing.T) {
 	result := fixture.RunTestWithBp(t, `
-		android_system_image_defaults {
+		android_filesystem_defaults {
 			name: "defaults",
 			multilib: {
 				common: {
@@ -447,3 +447,25 @@ func TestSystemImageDefaults(t *testing.T) {
 		android.AssertStringListContains(t, "missing entry", fs.entries, e)
 	}
 }
+
+func TestInconsistentPartitionTypesInDefaults(t *testing.T) {
+	fixture.ExtendWithErrorHandler(android.FixtureExpectsOneErrorPattern(
+		"doesn't match with the partition type")).
+		RunTestWithBp(t, `
+		android_filesystem_defaults {
+			name: "system_ext_def",
+			partition_type: "system_ext",
+		}
+
+		android_filesystem_defaults {
+			name: "system_def",
+			partition_type: "system",
+			defaults: ["system_ext_def"],
+		}
+
+		android_system_image {
+			name: "system",
+			defaults: ["system_def"],
+		}
+	`)
+}
diff --git a/filesystem/system_image.go b/filesystem/system_image.go
index 92bb206bc..5028a493e 100644
--- a/filesystem/system_image.go
+++ b/filesystem/system_image.go
@@ -21,7 +21,6 @@ import (
 
 type systemImage struct {
 	filesystem
-	android.DefaultableModuleBase
 
 	properties systemImageProperties
 }
@@ -40,7 +39,6 @@ func systemImageFactory() android.Module {
 	module.filesystem.buildExtraFiles = module.buildExtraFiles
 	module.filesystem.filterPackagingSpec = module.filterPackagingSpec
 	initFilesystemModule(&module.filesystem)
-	android.InitDefaultableModule(module)
 	return module
 }
 
@@ -102,17 +100,3 @@ func (s *systemImage) buildLinkerConfigFile(ctx android.ModuleContext, root andr
 func (s *systemImage) filterPackagingSpec(ps android.PackagingSpec) bool {
 	return ps.Partition() == "system"
 }
-
-type systemImageDefaults struct {
-	android.ModuleBase
-	android.DefaultsModuleBase
-}
-
-// android_system_image_defaults is a default module for android_system_image module.
-func systemImageDefaultsFactory() android.Module {
-	module := &systemImageDefaults{}
-	module.AddProperties(&android.PackagingProperties{})
-	module.AddProperties(&systemImageProperties{})
-	android.InitDefaultsModule(module)
-	return module
-}