1 files changed, 5 insertions, 2 deletions
diff --git a/src/core/lib/transport/metadata.cc b/src/core/lib/transport/metadata.cc
index 5455b2481b..2392f26c0b 100644
--- a/src/core/lib/transport/metadata.cc
+++ b/src/core/lib/transport/metadata.cc
@@ -352,11 +352,14 @@ static size_t get_base64_encoded_size(size_t raw_length) {
   return raw_length / 3 * 4 + tail_xtra[raw_length % 3];
 }
 
-size_t grpc_mdelem_get_size_in_hpack_table(grpc_mdelem elem) {
+size_t grpc_mdelem_get_size_in_hpack_table(grpc_mdelem elem,
+                                           bool use_true_binary_metadata) {
   size_t overhead_and_key = 32 + GRPC_SLICE_LENGTH(GRPC_MDKEY(elem));
   size_t value_len = GRPC_SLICE_LENGTH(GRPC_MDVALUE(elem));
   if (grpc_is_binary_header(GRPC_MDKEY(elem))) {
-    return overhead_and_key + get_base64_encoded_size(value_len);
+    return overhead_and_key + (use_true_binary_metadata
+                                   ? value_len + 1
+                                   : get_base64_encoded_size(value_len));
   } else {
     return overhead_and_key + value_len;
   }