diff --git a/reactos/ntoskrnl/cache/section/data.c b/reactos/ntoskrnl/cache/section/data.c
index b7dc9cefa77..07ffb7d64c3 100644
--- a/reactos/ntoskrnl/cache/section/data.c
+++ b/reactos/ntoskrnl/cache/section/data.c
@@ -869,7 +869,7 @@ MmExtendCacheSection(PROS_SECTION_OBJECT Section,
     MmLockSectionSegment(Segment);
     Segment->RawLength.QuadPart = NewSize->QuadPart;
     Segment->Length.QuadPart = MAX(Segment->Length.QuadPart,
-                                   PAGE_ROUND_UP(Segment->RawLength.LowPart));
+                                   (LONG64)PAGE_ROUND_UP(Segment->RawLength.QuadPart));
     MmUnlockSectionSegment(Segment);
     return STATUS_SUCCESS;
 }
diff --git a/reactos/ntoskrnl/mm/ARM3/section.c b/reactos/ntoskrnl/mm/ARM3/section.c
index 82f69629a98..3692faa1e45 100644
--- a/reactos/ntoskrnl/mm/ARM3/section.c
+++ b/reactos/ntoskrnl/mm/ARM3/section.c
@@ -1738,12 +1738,16 @@ MiRemoveMappedPtes(IN PVOID BaseAddress,
             /* Was the PDE invalid */
             if (PointerPde->u.Long == 0)
             {
+#if (_MI_PAGING_LEVELS == 2)
                 /* Find the system double-mapped PDE that describes this mapping */
                 SystemMapPde = &MmSystemPagePtes[((ULONG_PTR)PointerPde & (SYSTEM_PD_SIZE - 1)) / sizeof(MMPTE)];
 
                 /* Make it valid */
                 ASSERT(SystemMapPde->u.Hard.Valid == 1);
                 MI_WRITE_VALID_PDE(PointerPde, *SystemMapPde);
+#else
+                ASSERT(FALSE);
+#endif
             }
 
             /* Dereference the PDE and the PTE */
@@ -1791,7 +1795,8 @@ MiRemoveFromSystemSpace(IN PMMSESSION Session,
                         IN PVOID Base,
                         OUT PCONTROL_AREA *ControlArea)
 {
-    ULONG Hash, Size, Count = 0, Entry;
+    ULONG Hash, Size, Count = 0;
+    ULONG_PTR Entry;
     PAGED_CODE();
 
     /* Compute the hash for this entry and loop trying to find it */
@@ -1846,7 +1851,7 @@ MiUnmapViewInSystemSpace(IN PMMSESSION Session,
 
     /* Clear the bits for this mapping */
     RtlClearBits(Session->SystemSpaceBitMap,
-                 ((ULONG_PTR)MappedBase - (ULONG_PTR)Session->SystemSpaceViewStart) >> 16,
+                 (ULONG)(((ULONG_PTR)MappedBase - (ULONG_PTR)Session->SystemSpaceViewStart) >> 16),
                  Size);
 
     /* Convert the size from a bit size into the actual size */
diff --git a/reactos/ntoskrnl/mm/ARM3/virtual.c b/reactos/ntoskrnl/mm/ARM3/virtual.c
index 2785093ae47..c90c1be6e25 100644
--- a/reactos/ntoskrnl/mm/ARM3/virtual.c
+++ b/reactos/ntoskrnl/mm/ARM3/virtual.c
@@ -3579,7 +3579,7 @@ NtAllocateVirtualMemory(IN HANDLE ProcessHandle,
         //
         PointerPte = MI_GET_PROTOTYPE_PTE_FOR_VPN(FoundVad, StartingAddress >> PAGE_SHIFT);
         LastPte = MI_GET_PROTOTYPE_PTE_FOR_VPN(FoundVad, EndingAddress >> PAGE_SHIFT);
-        QuotaCharge = LastPte - PointerPte + 1;
+        QuotaCharge = (ULONG)(LastPte - PointerPte + 1);
         KeAcquireGuardedMutexUnsafe(&MmSectionCommitMutex);
 
         //
diff --git a/reactos/ntoskrnl/mm/rmap.c b/reactos/ntoskrnl/mm/rmap.c
index b8b7f5e2bcc..7d1c0b15901 100644
--- a/reactos/ntoskrnl/mm/rmap.c
+++ b/reactos/ntoskrnl/mm/rmap.c
@@ -125,7 +125,7 @@ MmPageOutPhysicalAddress(PFN_NUMBER Page)
    Type = MemoryArea->Type;
    if (Type == MEMORY_AREA_SECTION_VIEW)
    {
-      ULONG Entry;
+      ULONG_PTR Entry;
       Offset = MemoryArea->Data.SectionData.ViewOffset.QuadPart +
                ((ULONG_PTR)Address - (ULONG_PTR)MemoryArea->StartingAddress);
 
@@ -134,8 +134,8 @@ MmPageOutPhysicalAddress(PFN_NUMBER Page)
       /*
        * Get or create a pageop
        */
-      Entry = MmGetPageEntrySectionSegment
-          (MemoryArea->Data.SectionData.Segment, (PLARGE_INTEGER)&Offset);
+      Entry = MmGetPageEntrySectionSegment(MemoryArea->Data.SectionData.Segment,
+                                           (PLARGE_INTEGER)&Offset);
       if (Entry && IS_SWAP_FROM_SSE(Entry) && SWAPENTRY_FROM_SSE(Entry) == MM_WAIT_ENTRY)
       {
          MmUnlockSectionSegment(MemoryArea->Data.SectionData.Segment);
@@ -430,7 +430,7 @@ schema.  In short, this requires the address part to be 0xffffff00 + n
 where n is between 0 and 255.  When such an rmap exists, it specifies a
 segment rmap in which the process part is a pointer to a slice of a section
 page table, and the low 8 bits of the address represent a page index in the
-page table slice.  Together, this information is used by 
+page table slice.  Together, this information is used by
 MmGetSectionAssociation to determine which page entry points to this page in
 the segment page table.
 
diff --git a/reactos/ntoskrnl/mm/section.c b/reactos/ntoskrnl/mm/section.c
index 03990c6c9a9..039046394ef 100644
--- a/reactos/ntoskrnl/mm/section.c
+++ b/reactos/ntoskrnl/mm/section.c
@@ -1163,7 +1163,7 @@ MiReadPage(PMEMORY_AREA MemoryArea,
 NTSTATUS
 NTAPI
 MiReadPage(PMEMORY_AREA MemoryArea,
-           ULONG SegOffset,
+           ULONG_PTR SegOffset,
            PPFN_NUMBER Page)
 /*
  * FUNCTION: Read a page for a section backed memory area.
@@ -1685,7 +1685,7 @@ MmAccessFaultSectionView(PMMSUPPORT AddressSpace,
     */
    MmLockSectionSegment(Segment);
    Entry = MmGetPageEntrySectionSegment(Segment, &Offset);
-   
+
    /*
     * Wait for any other operations to complete
     */
@@ -2418,7 +2418,7 @@ MmAlterViewAttributes(PMMSUPPORT AddressSpace,
                      + MemoryArea->Data.SectionData.ViewOffset.QuadPart;
             Entry = MmGetPageEntrySectionSegment(Segment, &Offset);
             /*
-             * An MM_WAIT_ENTRY is ok in this case...  It'll just count as 
+             * An MM_WAIT_ENTRY is ok in this case...  It'll just count as
              * IS_SWAP_FROM_SSE and we'll do the right thing.
              */
             Page = MmGetPfnForProcess(Process, Address);