diff --git a/src/hb-aat-layout-trak-table.hh b/src/hb-aat-layout-trak-table.hh
index 16729d16f..c2c50bbb7 100644
--- a/src/hb-aat-layout-trak-table.hh
+++ b/src/hb-aat-layout-trak-table.hh
@@ -55,7 +55,7 @@ struct TrackTableEntry
 			unsigned int index,
 			unsigned int nSizes) const
   {
-    return hb_array_t<FWORD> ((base+valuesZ).arrayZ, nSizes)[index];
+    return hb_array_t<const FWORD> ((base+valuesZ).arrayZ, nSizes)[index];
   }
 
   public:
@@ -88,7 +88,7 @@ struct TrackData
 			       const void *base) const
   {
     unsigned int sizes = nSizes;
-    hb_array_t<Fixed> size_table ((base+sizeTable).arrayZ, sizes);
+    hb_array_t<const Fixed> size_table ((base+sizeTable).arrayZ, sizes);
 
     float s0 = size_table[idx].to_float ();
     float s1 = size_table[idx + 1].to_float ();
@@ -134,7 +134,7 @@ struct TrackData
     if (sizes == 1) return trackTableEntry->get_value (base, 0, sizes);
 
     /* TODO bfind() */
-    hb_array_t<Fixed> size_table ((base+sizeTable).arrayZ, sizes);
+    hb_array_t<const Fixed> size_table ((base+sizeTable).arrayZ, sizes);
     unsigned int size_index;
     for (size_index = 0; size_index < sizes - 1; size_index++)
       if (size_table[size_index].to_float () >= csspx)
diff --git a/src/hb-dsalgs.hh b/src/hb-dsalgs.hh
index 7e1b7eb1b..27c1a96ef 100644
--- a/src/hb-dsalgs.hh
+++ b/src/hb-dsalgs.hh
@@ -513,9 +513,9 @@ template <typename T>
 struct hb_array_t
 {
   inline hb_array_t (void) : arrayZ (nullptr), len (0) {}
-  inline hb_array_t (const T *array_, unsigned int len_) : arrayZ (array_), len (len_) {}
+  inline hb_array_t (T *array_, unsigned int len_) : arrayZ (array_), len (len_) {}
 
-  inline const T& operator [] (unsigned int i) const
+  inline T& operator [] (unsigned int i) const
   {
     if (unlikely (i >= len)) return Null(T);
     return arrayZ[i];
@@ -534,7 +534,7 @@ struct hb_array_t
 
   inline void free (void) { ::free ((void *) arrayZ); arrayZ = nullptr; len = 0; }
 
-  const T *arrayZ;
+  T *arrayZ;
   unsigned int len;
 };
 
diff --git a/src/hb-open-file.hh b/src/hb-open-file.hh
index 817791ab0..a973455d7 100644
--- a/src/hb-open-file.hh
+++ b/src/hb-open-file.hh
@@ -330,8 +330,8 @@ struct ResourceTypeRecord
   inline const ResourceRecord& get_resource_record (unsigned int i,
 						    const void *type_base) const
   {
-    return hb_array_t<ResourceRecord> ((type_base+resourcesZ).arrayZ,
-				       get_resource_count ()) [i];
+    return hb_array_t<const ResourceRecord> ((type_base+resourcesZ).arrayZ,
+					     get_resource_count ()) [i];
   }
 
   inline bool sanitize (hb_sanitize_context_t *c,