diff --git a/src/OT/Layout/GSUB/AlternateSet.hh b/src/OT/Layout/GSUB/AlternateSet.hh
index 4a9e9672e..fbc2b0a90 100644
--- a/src/OT/Layout/GSUB/AlternateSet.hh
+++ b/src/OT/Layout/GSUB/AlternateSet.hh
@@ -94,7 +94,7 @@ struct AlternateSet
   template <typename Iterator,
             hb_requires (hb_is_source_of (Iterator, hb_codepoint_t))>
   bool serialize (hb_serialize_context_t *c,
-                  Iterator alts)
+                  Iterator&& alts)
   {
     TRACE_SERIALIZE (this);
     return_trace (alternates.serialize (c, alts));
diff --git a/src/OT/Layout/GSUB/Ligature.hh b/src/OT/Layout/GSUB/Ligature.hh
index f373d921b..04450025e 100644
--- a/src/OT/Layout/GSUB/Ligature.hh
+++ b/src/OT/Layout/GSUB/Ligature.hh
@@ -149,7 +149,7 @@ struct Ligature
             hb_requires (hb_is_source_of (Iterator, hb_codepoint_t))>
   bool serialize (hb_serialize_context_t *c,
                   hb_codepoint_t ligature,
-                  Iterator components /* Starting from second */)
+                  Iterator&& components /* Starting from second */)
   {
     TRACE_SERIALIZE (this);
     if (unlikely (!c->extend_min (this))) return_trace (false);
diff --git a/src/OT/Layout/GSUB/Sequence.hh b/src/OT/Layout/GSUB/Sequence.hh
index 3d84a5e6e..393596783 100644
--- a/src/OT/Layout/GSUB/Sequence.hh
+++ b/src/OT/Layout/GSUB/Sequence.hh
@@ -132,7 +132,7 @@ struct Sequence
   template <typename Iterator,
             hb_requires (hb_is_source_of (Iterator, hb_codepoint_t))>
   bool serialize (hb_serialize_context_t *c,
-                  Iterator subst)
+                  Iterator&& subst)
   {
     TRACE_SERIALIZE (this);
     return_trace (substitute.serialize (c, subst));
diff --git a/src/OT/Layout/GSUB/SubstLookup.hh b/src/OT/Layout/GSUB/SubstLookup.hh
index 320685b86..7bd20c776 100644
--- a/src/OT/Layout/GSUB/SubstLookup.hh
+++ b/src/OT/Layout/GSUB/SubstLookup.hh
@@ -106,7 +106,7 @@ struct SubstLookup : Lookup
   bool serialize_single (hb_serialize_context_t *c,
                          uint32_t lookup_props,
                          Glyphs glyphs,
-                         Substitutes substitutes)
+                         Substitutes&& substitutes)
   {
     TRACE_SERIALIZE (this);
     if (unlikely (!Lookup::serialize (c, SubTable::Single, lookup_props, 1))) return_trace (false);
diff --git a/src/OT/glyf/glyf-helpers.hh b/src/OT/glyf/glyf-helpers.hh
index 181c33d06..405761acc 100644
--- a/src/OT/glyf/glyf-helpers.hh
+++ b/src/OT/glyf/glyf-helpers.hh
@@ -53,7 +53,7 @@ _add_head_and_set_loca_version (hb_subset_plan_t *plan, bool use_short_loca)
 template<typename Iterator,
 	 hb_requires (hb_is_source_of (Iterator, unsigned int))>
 static bool
-_add_loca_and_head (hb_subset_plan_t * plan, Iterator padded_offsets, bool use_short_loca)
+_add_loca_and_head (hb_subset_plan_t * plan, Iterator&& padded_offsets, bool use_short_loca)
 {
   unsigned num_offsets = padded_offsets.len () + 1;
   unsigned entry_size = use_short_loca ? 2 : 4;
diff --git a/src/hb-open-file.hh b/src/hb-open-file.hh
index 6eee5827c..7f37766df 100644
--- a/src/hb-open-file.hh
+++ b/src/hb-open-file.hh
@@ -122,7 +122,7 @@ typedef struct OpenTypeOffsetTable
 	    hb_requires ((hb_is_source_of<Iterator, hb_pair_t<hb_tag_t, hb_blob_t *>>::value))>
   bool serialize (hb_serialize_context_t *c,
 		  hb_tag_t sfnt_tag,
-		  Iterator it)
+		  Iterator&& it)
   {
     TRACE_SERIALIZE (this);
     /* Alloc 12 for the OTHeader. */
@@ -496,7 +496,7 @@ struct OpenTypeFontFile
 	    hb_requires ((hb_is_source_of<Iterator, hb_pair_t<hb_tag_t, hb_blob_t *>>::value))>
   bool serialize_single (hb_serialize_context_t *c,
 			 hb_tag_t sfnt_tag,
-			 Iterator items)
+			 Iterator&& items)
   {
     TRACE_SERIALIZE (this);
     assert (sfnt_tag != TTCTag);
diff --git a/src/hb-open-type.hh b/src/hb-open-type.hh
index d0d01a68c..8fe6eedd2 100644
--- a/src/hb-open-type.hh
+++ b/src/hb-open-type.hh
@@ -504,7 +504,7 @@ struct UnsizedArrayOf
   }
   template <typename Iterator,
 	    hb_requires (hb_is_source_of (Iterator, Type))>
-  bool serialize (hb_serialize_context_t *c, Iterator items)
+  bool serialize (hb_serialize_context_t *c, Iterator&& items)
   {
     TRACE_SERIALIZE (this);
     unsigned count = items.len ();
@@ -683,7 +683,7 @@ struct ArrayOf
   }
   template <typename Iterator,
 	    hb_requires (hb_is_source_of (Iterator, Type))>
-  HB_NODISCARD bool serialize (hb_serialize_context_t *c, Iterator items)
+  HB_NODISCARD bool serialize (hb_serialize_context_t *c, Iterator&& items)
   {
     TRACE_SERIALIZE (this);
     unsigned count = items.len ();
@@ -841,7 +841,7 @@ struct HeadlessArrayOf
   }
   template <typename Iterator,
 	    hb_requires (hb_is_source_of (Iterator, Type))>
-  bool serialize (hb_serialize_context_t *c, Iterator items)
+  bool serialize (hb_serialize_context_t *c, Iterator&& items)
   {
     TRACE_SERIALIZE (this);
     unsigned count = items.len ();
diff --git a/src/hb-ot-name-table.hh b/src/hb-ot-name-table.hh
index 1f2131ffc..e9cc26876 100644
--- a/src/hb-ot-name-table.hh
+++ b/src/hb-ot-name-table.hh
@@ -215,7 +215,7 @@ struct name
   template <typename Iterator,
 	    hb_requires (hb_is_source_of (Iterator, const NameRecord &))>
   bool serialize (hb_serialize_context_t *c,
-		  Iterator it,
+		  Iterator&& it,
 		  const void *src_string_pool)
   {
     TRACE_SERIALIZE (this);