diff --git a/lib/bigint.c b/lib/bigint.c
index 005f384..b86ab8e 100644
--- a/lib/bigint.c
+++ b/lib/bigint.c
@@ -1845,7 +1845,10 @@ hcl_oop_t hcl_mulints (hcl_t* hcl, hcl_oop_t x, hcl_oop_t y)
 		}
 
 	normal:
+		hcl_pushtmp (hcl, &x);
+		hcl_pushtmp (hcl, &y);
 		z = multiply_unsigned_integers (hcl, x, y);
+		hcl_poptmps (hcl, 2);
 		if (!z) return HCL_NULL;
 		if (HCL_OBJ_GET_FLAGS_BRAND(x) != HCL_OBJ_GET_FLAGS_BRAND(y))
 			HCL_OBJ_SET_FLAGS_BRAND (z, HCL_BRAND_NBIGINT);