diff --git a/src/EXTRA-DUMP/dump_xtc.cpp b/src/EXTRA-DUMP/dump_xtc.cpp
index 3d84ff67ef..3119a470dc 100644
--- a/src/EXTRA-DUMP/dump_xtc.cpp
+++ b/src/EXTRA-DUMP/dump_xtc.cpp
@@ -14,7 +14,7 @@
 
 /* ----------------------------------------------------------------------
    Contributing authors: Naveen Michaud-Agrawal (Johns Hopkins U)
-                         open-source XDR routines from
+                         Open Source XDR based I/O routines from
                            Frans van Hoesel (https://www.rug.nl/staff/f.h.j.van.hoesel/)
                            are included in this file
                          Axel Kohlmeyer (Temple U)
@@ -43,8 +43,8 @@
 
 using namespace LAMMPS_NS;
 
-#define EPS 1e-5
-#define XTC_MAGIC 1995
+static constexpr double EPS = 1.0e-5;
+static constexpr int XTC_MAGIC = 1995;
 
 #define MYMIN(a,b) ((a) < (b) ? (a) : (b))
 #define MYMAX(a,b) ((a) > (b) ? (a) : (b))
diff --git a/src/EXTRA-DUMP/xdr_compat.h b/src/EXTRA-DUMP/xdr_compat.h
index 4f41ade0a0..d600a4a404 100644
--- a/src/EXTRA-DUMP/xdr_compat.h
+++ b/src/EXTRA-DUMP/xdr_compat.h
@@ -111,10 +111,7 @@ typedef bool_t (*xdrproc_t)(XDR *, void *, ...);
  *
  * XDR          *xdrs;
  * xdr_int32_t  *int32p;
- * long         *longp;
- * char         *addr;
  * unsigned int  len;
- * unsigned int  pos;
  */
 
 #define xdr_getint32(xdrs, int32p) (*(xdrs)->x_ops->x_getint32)(xdrs, int32p)