diff --git a/reactos/include/ddk/wdm.h b/reactos/include/ddk/wdm.h
index e6b8cb91c1a..041e8ff0800 100644
--- a/reactos/include/ddk/wdm.h
+++ b/reactos/include/ddk/wdm.h
@@ -8064,7 +8064,7 @@ RtlCopyMemoryNonTemporal(
 #define RtlEqualLuid(Luid1, Luid2) \
     (((Luid1)->LowPart == (Luid2)->LowPart) && ((Luid1)->HighPart == (Luid2)->HighPart))
 
-/* ULONG
+/* LOGICAL
  * RtlEqualMemory(
  *     IN VOID UNALIGNED *Destination,
  *     IN CONST VOID UNALIGNED *Source,
diff --git a/reactos/include/ndk/rtlfuncs.h b/reactos/include/ndk/rtlfuncs.h
index 0f30638fe59..4da235f3f63 100644
--- a/reactos/include/ndk/rtlfuncs.h
+++ b/reactos/include/ndk/rtlfuncs.h
@@ -2516,7 +2516,8 @@ RtlDosSearchPath_U(
     OUT PWSTR *PartName
 );
 
-ULONG
+NTSYSAPI
+NTSTATUS
 NTAPI
 RtlDosSearchPath_Ustr(
     IN ULONG Flags,
diff --git a/reactos/include/xdk/rtlfuncs.h b/reactos/include/xdk/rtlfuncs.h
index 14ca70e7728..7d8d070e272 100644
--- a/reactos/include/xdk/rtlfuncs.h
+++ b/reactos/include/xdk/rtlfuncs.h
@@ -178,7 +178,7 @@ RtlCopyMemoryNonTemporal(
 #define RtlEqualLuid(Luid1, Luid2) \
     (((Luid1)->LowPart == (Luid2)->LowPart) && ((Luid1)->HighPart == (Luid2)->HighPart))
 
-/* ULONG
+/* LOGICAL
  * RtlEqualMemory(
  *     IN VOID UNALIGNED *Destination,
  *     IN CONST VOID UNALIGNED *Source,
diff --git a/reactos/lib/rtl/mem.c b/reactos/lib/rtl/mem.c
index 8f1e413f138..9544f7ecc55 100644
--- a/reactos/lib/rtl/mem.c
+++ b/reactos/lib/rtl/mem.c
@@ -85,7 +85,7 @@ VOID
 NTAPI
 RtlFillMemory (
    PVOID Destination,
-   ULONG Length,
+   SIZE_T Length,
    UCHAR Fill
 )
 {
@@ -101,12 +101,12 @@ VOID
 NTAPI
 RtlFillMemoryUlong (
    PVOID Destination,
-   ULONG Length,
+   SIZE_T Length,
    ULONG Fill
 )
 {
    PULONG Dest  = Destination;
-   ULONG  Count = Length / sizeof(ULONG);
+   SIZE_T Count = Length / sizeof(ULONG);
 
    while (Count > 0)
    {
@@ -126,7 +126,7 @@ NTAPI
 RtlMoveMemory (
    PVOID    Destination,
    CONST VOID  * Source,
-   ULONG    Length
+   SIZE_T   Length
 )
 {
    memmove (
@@ -160,7 +160,7 @@ VOID
 NTAPI
 RtlZeroMemory (
    PVOID Destination,
-   ULONG Length
+   SIZE_T Length
 )
 {
    RtlFillMemory (
diff --git a/reactos/lib/rtl/path.c b/reactos/lib/rtl/path.c
index 6a8b5676b02..e82e808787b 100644
--- a/reactos/lib/rtl/path.c
+++ b/reactos/lib/rtl/path.c
@@ -2011,7 +2011,7 @@ Quickie:
 /*
  * @implemented
  */
-ULONG
+NTSTATUS
 NTAPI
 RtlDosSearchPath_Ustr(IN ULONG Flags,
                       IN PUNICODE_STRING PathString,