diff --git a/programs/fileio.c b/programs/fileio.c
index 8a6b98d27ea96ebff79f5cbdc7152e93c27001a0..2f58509031d0c5953f7cc43b62f9406b3e0a10ef 100644
--- a/programs/fileio.c
+++ b/programs/fileio.c
@@ -1789,7 +1789,7 @@ static const char* checked_index(const char* options[], size_t length, size_t in
 
 #define INDEX(options, index) checked_index((options), sizeof(options)  / sizeof(char*), (index))
 
-void FIO_displayCompressionParameters(FIO_prefs_t* const prefs) {
+void FIO_displayCompressionParameters(const FIO_prefs_t* prefs) {
     static const char* formatOptions[5] = {ZSTD_EXTENSION, GZ_EXTENSION, XZ_EXTENSION,
                                            LZMA_EXTENSION, LZ4_EXTENSION};
     static const char* sparseOptions[3] = {" --no-sparse", "", " --sparse"};
diff --git a/programs/fileio.h b/programs/fileio.h
index 03527d042e8229d45518cd92a1ddbbf639d6bc9a..61094db83cba374f6aa1694153cb5510548f64be 100644
--- a/programs/fileio.h
+++ b/programs/fileio.h
@@ -108,7 +108,7 @@ void FIO_setExcludeCompressedFile(FIO_prefs_t* const prefs, int excludeCompresse
 void FIO_setAllowBlockDevices(FIO_prefs_t* const prefs, int allowBlockDevices);
 void FIO_setPatchFromMode(FIO_prefs_t* const prefs, int value);
 void FIO_setContentSize(FIO_prefs_t* const prefs, int value);
-void FIO_displayCompressionParameters(FIO_prefs_t* const prefs);
+void FIO_displayCompressionParameters(const FIO_prefs_t* prefs);
 
 /* FIO_ctx_t functions */
 void FIO_setNbFilesTotal(FIO_ctx_t* const fCtx, int value);