--- a/libinterp/corefcn/__isprimelarge__.cc	Sat Nov 05 18:35:09 2022 -0400
+++ b/libinterp/corefcn/__isprimelarge__.cc	Sun Nov 06 12:18:37 2022 +0100
@@ -213,9 +213,9 @@
 // factorization algorithm with Brent update.
 // The code is short and simple, but the math behind it is complicated.
 uint64_t
-pollardrho (uint64_t n, uint64_t c = 1ULL)
+pollardrho (uint64_t n, uint64_t c = UINT64_C (1))
 {
-  uint64_t i = 1ULL, j = 2ULL;  // cycle index values
+  uint64_t i = UINT64_C (1), j = UINT64_C (2);  // cycle index values
   uint64_t x = (c+1) % n;       // can also be rand () % n
   uint64_t y = x;               // other value in the chain
   uint64_t g = 0;               // GCD
@@ -238,10 +238,10 @@
           j <<= 1;
         }
 
-      if (g == n || i > 1000000ULL)  // cut losses, restart with a different c
+      if (g == n || i > UINT64_C (1000000))  // cut losses, restart with a different c
         return pollardrho (n, c + 2);
 
-      if (g > 1ULL)  // found GCD ==> exit loop properly
+      if (g > UINT64_C (1))  // found GCD ==> exit loop properly
         {
           error_unless (n % g == 0);  // theoretical possibility of GCD error
           return g;