diff --git a/src/bin/pg_dump/compress_io.c b/src/bin/pg_dump/compress_io.c
index 8f0d6d6210c..a7df600cc00 100644
--- a/src/bin/pg_dump/compress_io.c
+++ b/src/bin/pg_dump/compress_io.c
@@ -124,7 +124,8 @@ AllocateCompressor(const pg_compress_specification compression_spec,
  * out with ahwrite().
  */
 void
-ReadDataFromArchive(ArchiveHandle *AH, pg_compress_specification compression_spec,
+ReadDataFromArchive(ArchiveHandle *AH,
+					const pg_compress_specification compression_spec,
 					ReadFunc readF)
 {
 	if (compression_spec.algorithm == PG_COMPRESSION_NONE)