diff --git a/headers/os/interface/MenuField.h b/headers/os/interface/MenuField.h
index 770e74ef61..fac2aec127 100644
--- a/headers/os/interface/MenuField.h
+++ b/headers/os/interface/MenuField.h
@@ -111,7 +111,7 @@ private:
 	friend class _BMCMenuBar_;
 	friend class LabelLayoutItem;
 	friend class MenuBarLayoutItem;
-	friend class LayoutData;
+	friend struct LayoutData;
 
 								BMenuField(const char* name,
 									const char* label, BMenu* menu,
diff --git a/headers/os/package/hpkg/PackageContentHandler.h b/headers/os/package/hpkg/PackageContentHandler.h
index b09992b85c..2a0b6cb232 100644
--- a/headers/os/package/hpkg/PackageContentHandler.h
+++ b/headers/os/package/hpkg/PackageContentHandler.h
@@ -16,10 +16,10 @@ namespace BPackageKit {
 namespace BHPKG {
 
 
-class BPackageAttributeValue;
+struct BPackageAttributeValue;
 class BPackageEntry;
 class BPackageEntryAttribute;
-class BPackageInfoAttributeValue;
+struct BPackageInfoAttributeValue;
 
 
 class BLowLevelPackageContentHandler {
diff --git a/headers/os/package/hpkg/v1/PackageContentHandler.h b/headers/os/package/hpkg/v1/PackageContentHandler.h
index 6b46771951..1d700277d7 100644
--- a/headers/os/package/hpkg/v1/PackageContentHandler.h
+++ b/headers/os/package/hpkg/v1/PackageContentHandler.h
@@ -16,13 +16,13 @@ namespace BPackageKit {
 namespace BHPKG {
 
 
-class BPackageInfoAttributeValue;
+struct BPackageInfoAttributeValue;
 
 
 namespace V1 {
 
 
-class BPackageAttributeValue;
+struct BPackageAttributeValue;
 class BPackageEntry;
 class BPackageEntryAttribute;
 
diff --git a/src/add-ons/kernel/file_systems/cdda/kernel_interface.cpp b/src/add-ons/kernel/file_systems/cdda/kernel_interface.cpp
index 2bfad463e9..e43c8035a9 100644
--- a/src/add-ons/kernel/file_systems/cdda/kernel_interface.cpp
+++ b/src/add-ons/kernel/file_systems/cdda/kernel_interface.cpp
@@ -1508,7 +1508,7 @@ cdda_mount(fs_volume* fsVolume, const char* device, uint32 flags,
 static status_t
 cdda_unmount(fs_volume* _volume)
 {
-	struct Volume* volume = (struct Volume*)_volume->private_volume;
+	Volume* volume = (Volume*)_volume->private_volume;
 
 	TRACE(("cdda_unmount: entry fs = %p\n", _volume));
 	delete volume;
diff --git a/src/add-ons/kernel/file_systems/nfs4/FileInfo.h b/src/add-ons/kernel/file_systems/nfs4/FileInfo.h
index d98574817b..ca41768fd2 100644
--- a/src/add-ons/kernel/file_systems/nfs4/FileInfo.h
+++ b/src/add-ons/kernel/file_systems/nfs4/FileInfo.h
@@ -34,7 +34,7 @@ struct FileHandle {
 	inline	bool		operator<(const FileHandle& handle) const;
 };
 
-class InodeNames;
+struct InodeNames;
 
 struct InodeName : public SinglyLinkedListLinkImpl<InodeName> {
 				InodeName(InodeNames* parent, const char* name);
diff --git a/src/add-ons/kernel/file_systems/packagefs/indices/AttributeIndexer.h b/src/add-ons/kernel/file_systems/packagefs/indices/AttributeIndexer.h
index ccd5dbc438..614c7f2234 100644
--- a/src/add-ons/kernel/file_systems/packagefs/indices/AttributeIndexer.h
+++ b/src/add-ons/kernel/file_systems/packagefs/indices/AttributeIndexer.h
@@ -12,7 +12,7 @@
 
 
 class AttributeIndex;
-class AttributeIndexTreeValue;
+struct AttributeIndexTreeValue;
 class IndexedAttributeOwner;
 
 
diff --git a/src/add-ons/kernel/file_systems/packagefs/indices/NameIndex.h b/src/add-ons/kernel/file_systems/packagefs/indices/NameIndex.h
index 76766371e6..021ff16663 100644
--- a/src/add-ons/kernel/file_systems/packagefs/indices/NameIndex.h
+++ b/src/add-ons/kernel/file_systems/packagefs/indices/NameIndex.h
@@ -38,7 +38,7 @@ private:
 			struct IteratorPolicy;
 			struct Iterator;
 
-			friend class IteratorPolicy;
+			friend struct IteratorPolicy;
 
 			void				_UpdateLiveQueries(Node* entry,
 									const char* oldName, const char* newName);