diff --git a/src/H5FDcore.c b/src/H5FDcore.c
index ebf9921936..20bb5f22d8 100644
--- a/src/H5FDcore.c
+++ b/src/H5FDcore.c
@@ -1607,7 +1607,7 @@ H5FD__core_truncate(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t closing
                 BOOL  bError;           /* Boolean error flag */
 
                 /* Windows uses this odd QuadPart union for 32/64-bit portability */
-                li.QuadPart = (__int64)file->eoa;
+                li.QuadPart = (LONGLONG)file->eoa;
 
                 /* Extend the file to make sure it's large enough.
                  *
diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index 28ba5d8aaf..90c4d0fe97 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -1626,7 +1626,7 @@ H5FD__log_truncate(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t H5_ATTR_
                                      */
 
             /* Windows uses this odd QuadPart union for 32/64-bit portability */
-            li.QuadPart = (__int64)file->eoa;
+            li.QuadPart = (LONGLONG)file->eoa;
 
             /* Extend the file to make sure it's large enough.
              *
diff --git a/src/H5FDsec2.c b/src/H5FDsec2.c
index 1d97f83a4c..e83411ccb4 100644
--- a/src/H5FDsec2.c
+++ b/src/H5FDsec2.c
@@ -915,7 +915,7 @@ H5FD__sec2_truncate(H5FD_t *_file, hid_t H5_ATTR_UNUSED dxpl_id, hbool_t H5_ATTR
         BOOL  bError;           /* Boolean error flag */
 
         /* Windows uses this odd QuadPart union for 32/64-bit portability */
-        li.QuadPart = (__int64)file->eoa;
+        li.QuadPart = (LONGLONG)file->eoa;
 
         /* Extend the file to make sure it's large enough.
          *
diff --git a/src/H5FDstdio.c b/src/H5FDstdio.c
index 6624685d70..39dba4725a 100644
--- a/src/H5FDstdio.c
+++ b/src/H5FDstdio.c
@@ -1066,7 +1066,7 @@ H5FD_stdio_truncate(H5FD_t *_file, hid_t /*UNUSED*/ dxpl_id, hbool_t /*UNUSED*/
             rewind(file->fp);
 
             /* Windows uses this odd QuadPart union for 32/64-bit portability */
-            li.QuadPart = (__int64)file->eoa;
+            li.QuadPart = (LONGLONG)file->eoa;
 
             /* Extend the file to make sure it's large enough.
              *