diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index 97d2971be..bc80586ab 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -993,10 +993,46 @@ struct hb_collect_features_context_t
 {
   hb_collect_features_context_t (hb_face_t *face,
 				 hb_tag_t   table_tag,
-				 hb_set_t  *feature_indexes_)
+				 hb_set_t  *feature_indices_,
+                                 const hb_tag_t *features)
+
     : g (get_gsubgpos_table (face, table_tag)),
-      feature_indexes (feature_indexes_),
-      script_count (0),langsys_count (0), feature_index_count (0) {}
+      feature_indices (feature_indices_),
+      has_feature_filter (false),
+      script_count (0),langsys_count (0), feature_index_count (0)
+  {
+    compute_feature_filter (features);
+  }
+
+  void compute_feature_filter (const hb_tag_t *features)
+  {
+    if (features == nullptr)
+    {
+      has_feature_filter = false;
+      return;
+    }
+
+    has_feature_filter = true;
+    for (; *features; features++)
+    {
+      hb_tag_t tag = *features;
+      unsigned index;
+      g.find_feature_index (tag, &index);
+      if (index == OT::Index::NOT_FOUND_INDEX) continue;
+
+      feature_indices_filter.add(index);
+      for (int i = (int) index - 1; i >= 0; i--)
+      {
+        if (g.get_feature_tag (i) != tag) break;
+        feature_indices_filter.add(i);
+      }
+      for (unsigned i = index + 1; i < g.get_feature_count (); i++)
+      {
+        if (g.get_feature_tag (i) != tag) break;
+        feature_indices_filter.add(i);
+      }
+    }
+  }
 
   bool visited (const OT::Script &s)
   {
@@ -1045,7 +1081,9 @@ struct hb_collect_features_context_t
 
   public:
   const OT::GSUBGPOS &g;
-  hb_set_t           *feature_indexes;
+  hb_set_t *feature_indices;
+  hb_set_t  feature_indices_filter;
+  bool has_feature_filter;
 
   private:
   hb_set_t visited_script;
@@ -1057,37 +1095,31 @@ struct hb_collect_features_context_t
 
 static void
 langsys_collect_features (hb_collect_features_context_t *c,
-			  const OT::LangSys  &l,
-			  const hb_tag_t     *features)
+			  const OT::LangSys  &l)
 {
   if (c->visited (l)) return;
 
-  if (!features)
+  if (!c->has_feature_filter)
   {
     /* All features. */
     if (l.has_required_feature () && !c->visited_feature_indices (1))
-      c->feature_indexes->add (l.get_required_feature_index ());
+      c->feature_indices->add (l.get_required_feature_index ());
 
+    // TODO(garretrieger): filter out indices >= feature count?
     if (!c->visited_feature_indices (l.featureIndex.len))
-      l.add_feature_indexes_to (c->feature_indexes);
+      l.add_feature_indexes_to (c->feature_indices);
   }
   else
   {
-    /* Ugh. Any faster way? */
-    for (; *features; features++)
+    if (c->feature_indices_filter.is_empty()) return;
+    unsigned int num_features = l.get_feature_count ();
+    for (unsigned int i = 0; i < num_features; i++)
     {
-      hb_tag_t feature_tag = *features;
-      unsigned int num_features = l.get_feature_count ();
-      for (unsigned int i = 0; i < num_features; i++)
-      {
-	unsigned int feature_index = l.get_feature_index (i);
+      unsigned int feature_index = l.get_feature_index (i);
+      if (!c->feature_indices_filter.has (feature_index)) continue;
 
-	if (feature_tag == c->g.get_feature_tag (feature_index))
-	{
-	  c->feature_indexes->add (feature_index);
-	  break;
-	}
-      }
+      c->feature_indices->add (feature_index);
+      c->feature_indices_filter.del (feature_index);
     }
   }
 }
@@ -1095,8 +1127,7 @@ langsys_collect_features (hb_collect_features_context_t *c,
 static void
 script_collect_features (hb_collect_features_context_t *c,
 			 const OT::Script   &s,
-			 const hb_tag_t *languages,
-			 const hb_tag_t *features)
+			 const hb_tag_t *languages)
 {
   if (c->visited (s)) return;
 
@@ -1105,14 +1136,13 @@ script_collect_features (hb_collect_features_context_t *c,
     /* All languages. */
     if (s.has_default_lang_sys ())
       langsys_collect_features (c,
-				s.get_default_lang_sys (),
-				features);
+				s.get_default_lang_sys ());
+
 
     unsigned int count = s.get_lang_sys_count ();
     for (unsigned int language_index = 0; language_index < count; language_index++)
       langsys_collect_features (c,
-				s.get_lang_sys (language_index),
-				features);
+				s.get_lang_sys (language_index));
   }
   else
   {
@@ -1121,8 +1151,8 @@ script_collect_features (hb_collect_features_context_t *c,
       unsigned int language_index;
       if (s.find_lang_sys_index (*languages, &language_index))
 	langsys_collect_features (c,
-				  s.get_lang_sys (language_index),
-				  features);
+				  s.get_lang_sys (language_index));
+
     }
   }
 }
@@ -1153,7 +1183,7 @@ hb_ot_layout_collect_features (hb_face_t      *face,
 			       const hb_tag_t *features,
 			       hb_set_t       *feature_indexes /* OUT */)
 {
-  hb_collect_features_context_t c (face, table_tag, feature_indexes);
+  hb_collect_features_context_t c (face, table_tag, feature_indexes, features);
   if (!scripts)
   {
     /* All scripts. */
@@ -1161,8 +1191,7 @@ hb_ot_layout_collect_features (hb_face_t      *face,
     for (unsigned int script_index = 0; script_index < count; script_index++)
       script_collect_features (&c,
 			       c.g.get_script (script_index),
-			       languages,
-			       features);
+			       languages);
   }
   else
   {
@@ -1172,8 +1201,7 @@ hb_ot_layout_collect_features (hb_face_t      *face,
       if (c.g.find_script_index (*scripts, &script_index))
 	script_collect_features (&c,
 				 c.g.get_script (script_index),
-				 languages,
-				 features);
+				 languages);
     }
   }
 }
diff --git a/test/fuzzing/fonts/clusterfuzz-testcase-minimized-hb-subset-fuzzer-5241922561114112 b/test/fuzzing/fonts/clusterfuzz-testcase-minimized-hb-subset-fuzzer-5241922561114112
new file mode 100644
index 000000000..122a9680b
Binary files /dev/null and b/test/fuzzing/fonts/clusterfuzz-testcase-minimized-hb-subset-fuzzer-5241922561114112 differ