diff --git a/Changelog.md b/Changelog.md
index 22c8dfa2..7f6332b9 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -20,6 +20,7 @@ Next Release
 - New shortcuts for ***O**utput Highlighting* and ***P**rogress Reformatting* on Processing window (Dendraspis)
 - New shortcuts for existing actions on Jobs window (stax76)
 - Fix x265 Slower preset default values (tkozybski)
+- Fix x265 params --atc-sei and --pic-struct wrong parameter type (Dendraspis, [#593](/../../issues/593))
 - Removal of Menu Styles (Dendraspis, [#589](/../../issues/589))
 - In quality mode main dialog shows count and type of active subtitles (stax76)
 - Main dialog and code editor show script info with F2 key and
diff --git a/Source/Encoding/x265Enc.vb b/Source/Encoding/x265Enc.vb
index 45437f4a..e91ef44f 100644
--- a/Source/Encoding/x265Enc.vb
+++ b/Source/Encoding/x265Enc.vb
@@ -1058,9 +1058,9 @@ Public Class x265Params
                     minLuma, maxLuma, MaxCLL, MaxFALL,
                     New BoolParam With {.Switch = "--hdr10-opt", .NoSwitch = "--no-hdr10-opt", .Text = "Block-level luma and chroma QP optimization for HDR10 content"},
                     New BoolParam With {.Switch = "--dhdr10-opt", .Text = "Limit frames for which tone mapping information is inserted as SEI message"},
-                    New BoolParam With {.Switch = "--atc-sei", .Text = "Emit the alternative transfer characteristics SEI message"},
                     New BoolParam With {.Switch = "--cll", .NoSwitch = "--no-cll", .Text = "Emit content light level info SEI", .Init = True},
-                    New BoolParam With {.Switch = "--pic-struct", .Text = "Set the picture structure and emits it in the picture timing SEI message"})
+                    New NumParam With {.Switch = "--atc-sei", .Text = "Emit the alternative transfer characteristics SEI message", .Init = -1, .Config = {-1, 100, 1}},
+                    New NumParam With {.Switch = "--pic-struct", .Text = "Set the picture structure and emits it in the picture timing SEI message", .Init = -1, .Config = {-1, 100, 1}})
                 Add("VUI 2",
                     New StringParam With {.Switch = "--nalu-file", .Text = "Nalu File", .BrowseFile = True},
                     New StringParam With {.Switch = "--sar", .Text = "Sample Aspect Ratio", .Init = "auto", .Menu = s.ParMenu, .ArgsFunc = AddressOf GetSAR},