diff --git a/Source/kwsys/hashtable.hxx.in b/Source/kwsys/hashtable.hxx.in
index 307f6bc1f..7e7dc4259 100644
--- a/Source/kwsys/hashtable.hxx.in
+++ b/Source/kwsys/hashtable.hxx.in
@@ -423,7 +423,7 @@ static const unsigned long _stl_prime_list[_stl_num_primes] =
 
 return &_stl_prime_list[0]; }
 
-inline size_t _stl_next_prime(size_t __n)
+static inline size_t _stl_next_prime(size_t __n)
 {
   const unsigned long* __first = get_stl_prime_list();
   const unsigned long* __last = get_stl_prime_list() + (int)_stl_num_primes;