diff --git a/src/hb-aat-layout-common-private.hh b/src/hb-aat-layout-common-private.hh
index b5395bba5..1ea8318fb 100644
--- a/src/hb-aat-layout-common-private.hh
+++ b/src/hb-aat-layout-common-private.hh
@@ -120,7 +120,7 @@ struct BinSearchArrayOf
       else
 	return p;
     }
-    return NULL;
+    return nullptr;
   }
 
   private:
diff --git a/src/hb-buffer-deserialize-json.rl b/src/hb-buffer-deserialize-json.rl
index 91b350f5a..0f7d48ee2 100644
--- a/src/hb-buffer-deserialize-json.rl
+++ b/src/hb-buffer-deserialize-json.rl
@@ -106,7 +106,7 @@ _hb_buffer_deserialize_glyphs_json (hb_buffer_t *buffer,
   const char *p = buf, *pe = buf + buf_len;
 
   /* Ensure we have positions. */
-  (void) hb_buffer_get_glyph_positions (buffer, NULL);
+  (void) hb_buffer_get_glyph_positions (buffer, nullptr);
 
   while (p < pe && ISSPACE (*p))
     p++;
@@ -115,7 +115,7 @@ _hb_buffer_deserialize_glyphs_json (hb_buffer_t *buffer,
     *end_ptr = ++p;
   }
 
-  const char *tok = NULL;
+  const char *tok = nullptr;
   int cs;
   hb_glyph_info_t info = {0};
   hb_glyph_position_t pos = {0};
diff --git a/src/hb-buffer-deserialize-text.rl b/src/hb-buffer-deserialize-text.rl
index 8a682f737..fd9be42df 100644
--- a/src/hb-buffer-deserialize-text.rl
+++ b/src/hb-buffer-deserialize-text.rl
@@ -100,7 +100,7 @@ _hb_buffer_deserialize_glyphs_text (hb_buffer_t *buffer,
   const char *p = buf, *pe = buf + buf_len;
 
   /* Ensure we have positions. */
-  (void) hb_buffer_get_glyph_positions (buffer, NULL);
+  (void) hb_buffer_get_glyph_positions (buffer, nullptr);
 
   while (p < pe && ISSPACE (*p))
     p++;
@@ -109,7 +109,7 @@ _hb_buffer_deserialize_glyphs_text (hb_buffer_t *buffer,
     *end_ptr = ++p;
   }
 
-  const char *eof = pe, *tok = NULL;
+  const char *eof = pe, *tok = nullptr;
   int cs;
   hb_glyph_info_t info = {0};
   hb_glyph_position_t pos = {0};