diff --git a/src/segment-map.c b/src/segment-map.c
index ff6144a4..43cb3bd9 100644
--- a/src/segment-map.c
+++ b/src/segment-map.c
@@ -29,14 +29,15 @@ terms of the MIT license. A copy of the license can be found in the file
 #define MI_SEGMENT_MAP_PART_BITS      (8*MI_SEGMENT_MAP_PART_SIZE)
 #define MI_SEGMENT_MAP_PART_ENTRIES   (MI_SEGMENT_MAP_PART_SIZE / MI_INTPTR_SIZE)
 #define MI_SEGMENT_MAP_PART_BIT_SPAN  (MI_SEGMENT_ALIGN)
-#define MI_SEGMENT_MAP_PART_SPAN      (MI_SEGMENT_MAP_PART_BITS * MI_SEGMENT_MAP_PART_BIT_SPAN)
 
-#if MI_SEGMENT_MAP_PART_SPAN > MI_SEGMENT_MAP_MAX_ADDRESS
-#define MI_SEGMENT_MAP_MAX_PARTS      (1)
+#if (MI_SEGMENT_PART_BITS < (MI_SEGMENT_MAP_MAX_ADDRESS / MI_SEGMENT_MAP_PART_BIT_SPAN)) // prevent overflow on 32-bit (issue #1017)
+#define MI_SEGMENT_MAP_PART_SPAN      (MI_SEGMENT_MAP_PART_BITS * MI_SEGMENT_MAP_PART_BIT_SPAN)
 #else
-#define MI_SEGMENT_MAP_MAX_PARTS      ((MI_SEGMENT_MAP_MAX_ADDRESS / MI_SEGMENT_MAP_PART_SPAN) + 1)
+#define MI_SEGMENT_MAP_PART_SPAN      MI_SEGMENT_MAP_MAX_ADDRESS
 #endif
 
+#define MI_SEGMENT_MAP_MAX_PARTS      ((MI_SEGMENT_MAP_MAX_ADDRESS / MI_SEGMENT_MAP_PART_SPAN) + 1)
+
 // A part of the segment map.
 typedef struct mi_segmap_part_s {
   mi_memid_t memid;