diff --git a/bld/gen_full.iss b/bld/gen_full.iss
index bd5044ed..a66f466e 100644
--- a/bld/gen_full.iss
+++ b/bld/gen_full.iss
@@ -29,9 +29,9 @@ RestartApplications=False
 Uninstallable=TDIsUninstallable
 UninstallDisplayName={#MyAppName}
 UninstallDisplayIcon={app}\{#MyAppExeName}
-Compression=lzma
+Compression=lzma2/ultra
 SolidCompression=yes
-InternalCompressLevel=max
+InternalCompressLevel=normal
 MinVersion=0,6.1
 
 #include <idp.iss>
diff --git a/bld/gen_port.iss b/bld/gen_port.iss
index 56bab0ee..d1693984 100644
--- a/bld/gen_port.iss
+++ b/bld/gen_port.iss
@@ -29,9 +29,9 @@ RestartApplications=False
 Uninstallable=no
 UsePreviousAppDir=no
 PrivilegesRequired=lowest
-Compression=lzma
+Compression=lzma2/ultra
 SolidCompression=yes
-InternalCompressLevel=max
+InternalCompressLevel=normal
 MinVersion=0,6.1
 
 #include <idp.iss>