diff --git a/git-gui.sh b/git-gui.sh
index 789c177b3b2eeb90a61ec94fd3b5e0f03773fa63..c190cbe23f0c67f3866311506e4c5eaf47c87e80 100755
--- a/git-gui.sh
+++ b/git-gui.sh
@@ -850,6 +850,7 @@ set default_config(gui.fastcopyblame) false
 set default_config(gui.copyblamethreshold) 40
 set default_config(gui.blamehistoryctx) 7
 set default_config(gui.diffcontext) 5
+set default_config(gui.diffopts) {}
 set default_config(gui.commitmsgwidth) 75
 set default_config(gui.newbranchtemplate) {}
 set default_config(gui.spellingdictionary) {}
diff --git a/lib/diff.tcl b/lib/diff.tcl
index f5ed5d1dc66844fb58a2605285eb460fe14112a4..ec4405567a9b86a9bfd8bf50815b3c9c14e2df40 100644
--- a/lib/diff.tcl
+++ b/lib/diff.tcl
@@ -309,6 +309,7 @@ proc start_show_diff {cont_info {add_opts {}}} {
 
 	lappend cmd -p
 	lappend cmd --color
+	set cmd [concat $cmd $repo_config(gui.diffopts)]
 	if {$repo_config(gui.diffcontext) >= 1} {
 		lappend cmd "-U$repo_config(gui.diffcontext)"
 	}
diff --git a/lib/option.tcl b/lib/option.tcl
index 719103a4220cd3b84734c37e78e32773a8f23a47..fb0677675ad7eddc4187cc00d0e8e039050b80e2 100644
--- a/lib/option.tcl
+++ b/lib/option.tcl
@@ -153,6 +153,7 @@ proc do_options {} {
 		{i-20..200 gui.copyblamethreshold {mc "Minimum Letters To Blame Copy On"}}
 		{i-0..300 gui.blamehistoryctx {mc "Blame History Context Radius (days)"}}
 		{i-1..99 gui.diffcontext {mc "Number of Diff Context Lines"}}
+		{t gui.diffopts {mc "Additional Diff Parameters"}}
 		{i-0..99 gui.commitmsgwidth {mc "Commit Message Text Width"}}
 		{t gui.newbranchtemplate {mc "New Branch Name Template"}}
 		{c gui.encoding {mc "Default File Contents Encoding"}}