diff --git a/src/gcarray.c b/src/gcarray.c
index c443eeb..cf220c7 100644
--- a/src/gcarray.c
+++ b/src/gcarray.c
@@ -112,7 +112,7 @@ LispPTR aref1(LispPTR array, int index) {
   if (index >= actarray->totalsize) {
     printf("Invalid index in GC's AREF1:  0x%x\n", index);
     printf(" Array size limit:  0x%x\n", actarray->totalsize);
-    printf(" Array ptr: 0x%lx\n", (UNSIGNED)array);
+    printf(" Array ptr: 0x%x\n", array);
     printf(" Array 68K ptr: %p\n", actarray);
     printf("base:     0x%x\n", actarray->base);
     printf("offset:   0x%x\n", actarray->offset);