diff --git a/daemon/readwrite.c b/daemon/readwrite.c
index 5929a8c..d205a38 100644
--- a/daemon/readwrite.c
+++ b/daemon/readwrite.c
@@ -53,7 +53,7 @@ static int parse_rw(unsigned char *buffer, uint32_t length, nfs41_upcall *upcall
     status = safe_read(&buffer, &length, &args->buffer, sizeof(args->buffer));
     if (status) goto out;
 
-    dprintf(1, "parsing %s len=%ld offset=%ld buf=%p\n", 
+    dprintf(1, "parsing %s len=%lu offset=%llu buf=%p\n", 
             opcode2string(upcall->opcode), args->len, args->offset, args->buffer);
 out:
     return status;
diff --git a/daemon/upcall.h b/daemon/upcall.h
index ed0f0c4..e2154ba 100644
--- a/daemon/upcall.h
+++ b/daemon/upcall.h
@@ -69,7 +69,7 @@ typedef struct __close_upcall_args {
 
 typedef struct __readwrite_upcall_args {
     unsigned char *buffer;
-    LONGLONG offset;
+    ULONGLONG offset;
     ULONG len;
     ULONG out_len;
     ULONGLONG ctime;
diff --git a/sys/nfs41_driver.c b/sys/nfs41_driver.c
index c6a607e..574aa1e 100644
--- a/sys/nfs41_driver.c
+++ b/sys/nfs41_driver.c
@@ -172,7 +172,7 @@ typedef struct _updowncall_entry {
         struct {                       
             PMDL MdlAddress;
             PVOID buf;
-            LONGLONG offset;
+            ULONGLONG offset;
             ULONG len;
             PRX_CONTEXT rxcontext;
             ULONGLONG ChangeTime;
@@ -743,7 +743,7 @@ NTSTATUS marshal_nfs41_rw(
     *len = header_len;
 
 #ifdef DEBUG_MARSHAL_DETAIL
-    DbgP("marshal_nfs41_rw: len=%u offset=%lu MdlAddress=%p Userspace=%p\n", 
+    DbgP("marshal_nfs41_rw: len=%lu offset=%llu MdlAddress=%p Userspace=%p\n", 
          entry->u.ReadWrite.len, entry->u.ReadWrite.offset, 
          entry->u.ReadWrite.MdlAddress, entry->u.ReadWrite.buf);
 #endif