diff --git a/goal_src/jak2/levels/city/common/height-map.gc b/goal_src/jak2/levels/city/common/height-map.gc
index f600684609..2dfa6089ca 100644
--- a/goal_src/jak2/levels/city/common/height-map.gc
+++ b/goal_src/jak2/levels/city/common/height-map.gc
@@ -103,7 +103,8 @@
          (a1-7
            (the-as
              (pointer int8)
-             (+ (+ (min a2-0 (+ v1-0 -2)) (* (min a1-1 (+ a3-0 -2)) v1-0) 0) (the-as int (the-as pointer (-> this data))))
+             ;; og:preserve-this prevent array out-of-bounds access
+             (+ (+ (min (max 0 a2-0) (+ v1-0 -2)) (* (min (max 0 a1-1) (+ a3-0 -2)) v1-0) 0) (the-as int (the-as pointer (-> this data))))
              )
            )
          (f3-3 (the float (-> a1-7 0)))
diff --git a/goal_src/jak3/levels/city/common/height-map.gc b/goal_src/jak3/levels/city/common/height-map.gc
index 0002e25e6b..10926a9b27 100644
--- a/goal_src/jak3/levels/city/common/height-map.gc
+++ b/goal_src/jak3/levels/city/common/height-map.gc
@@ -95,7 +95,8 @@
          (a1-7
            (the-as
              (pointer int8)
-             (+ (+ (min a2-0 (+ v1-0 -2)) (* (min a1-1 (+ a3-0 -2)) v1-0) 0) (the-as int (the-as pointer (-> this data))))
+             ;; og:preserve-this prevent array out-of-bounds access
+             (+ (+ (min (max 0 a2-0) (+ v1-0 -2)) (* (min (max 0 a1-1) (+ a3-0 -2)) v1-0) 0) (the-as int (the-as pointer (-> this data))))
              )
            )
          (f3-3 (the float (-> a1-7 0)))