diff --git a/polly/lib/External/isl/isl_coalesce.c b/polly/lib/External/isl/isl_coalesce.c
--- a/polly/lib/External/isl/isl_coalesce.c
+++ b/polly/lib/External/isl/isl_coalesce.c
@@ -3178,7 +3178,7 @@
 			return isl_stat_error;
 		info->bmap = isl_basic_map_cow(info->bmap);
 		info->bmap = isl_basic_map_free_inequality(info->bmap, 2 * n);
-		if (info->bmap < 0)
+		if (info->bmap->n_eq < 0)
 			return isl_stat_error;
 
 		return fix_constant_divs(info, n, expanded);