diff --git a/ntoskrnl/mm/ARM3/section.c b/ntoskrnl/mm/ARM3/section.c
index 02ead9a70a5..fe7e8b46145 100644
--- a/ntoskrnl/mm/ARM3/section.c
+++ b/ntoskrnl/mm/ARM3/section.c
@@ -1700,7 +1700,7 @@ PFILE_OBJECT
 NTAPI
 MmGetFileObjectForSection(IN PVOID SectionObject)
 {
-    PSECTION_OBJECT Section;
+    PSECTION Section;
     ASSERT(KeGetCurrentIrql() == PASSIVE_LEVEL);
     ASSERT(SectionObject != NULL);
 
@@ -1773,7 +1773,7 @@ VOID
 NTAPI
 MmGetImageInformation (OUT PSECTION_IMAGE_INFORMATION ImageInformation)
 {
-    PSECTION_OBJECT SectionObject;
+    PSECTION SectionObject;
 
     /* Get the section object of this process*/
     SectionObject = PsGetCurrentProcess()->SectionObject;
diff --git a/ntoskrnl/ps/process.c b/ntoskrnl/ps/process.c
index 179fd1d8fa4..0e6f112a53b 100644
--- a/ntoskrnl/ps/process.c
+++ b/ntoskrnl/ps/process.c
@@ -358,7 +358,7 @@ PspCreateProcess(OUT PHANDLE ProcessHandle,
     PEPROCESS Process, Parent;
     PVOID ExceptionPortObject;
     PDEBUG_OBJECT DebugObject;
-    PSECTION_OBJECT SectionObject;
+    PSECTION SectionObject;
     NTSTATUS Status, AccessStatus;
     ULONG_PTR DirectoryTableBase[2] = {0,0};
     KAFFINITY Affinity;
diff --git a/sdk/include/ndk/mmtypes.h b/sdk/include/ndk/mmtypes.h
index ca62ebdf5ce..3e9fabf1c02 100644
--- a/sdk/include/ndk/mmtypes.h
+++ b/sdk/include/ndk/mmtypes.h
@@ -623,19 +623,6 @@ typedef struct _SEGMENT_OBJECT
     PMMSUBSECTION_FLAGS MmSubSectionFlags;
 } SEGMENT_OBJECT, *PSEGMENT_OBJECT;
 
-//
-// Section Object
-//
-typedef struct _SECTION_OBJECT
-{
-    PVOID StartingVa;
-    PVOID EndingVa;
-    PVOID Parent;
-    PVOID LeftChild;
-    PVOID RightChild;
-    PSEGMENT_OBJECT Segment;
-} SECTION_OBJECT, *PSECTION_OBJECT;
-
 //
 // Generic Address Range Structure
 //