diff --git a/sys/amd64/linux/syscalls.conf b/sys/amd64/linux/syscalls.conf
--- a/sys/amd64/linux/syscalls.conf
+++ b/sys/amd64/linux/syscalls.conf
@@ -9,3 +9,4 @@
 switchname="linux_sysent"
 namesname="linux_syscallnames"
 systrace="linux_systrace_args.c"
+compat_set=""
diff --git a/sys/amd64/linux32/syscalls.conf b/sys/amd64/linux32/syscalls.conf
--- a/sys/amd64/linux32/syscalls.conf
+++ b/sys/amd64/linux32/syscalls.conf
@@ -9,3 +9,4 @@
 switchname="linux32_sysent"
 namesname="linux32_syscallnames"
 systrace="linux32_systrace_args.c"
+compat_set=""
diff --git a/sys/arm64/linux/syscalls.conf b/sys/arm64/linux/syscalls.conf
--- a/sys/arm64/linux/syscalls.conf
+++ b/sys/arm64/linux/syscalls.conf
@@ -9,3 +9,4 @@
 switchname="linux_sysent"
 namesname="linux_syscallnames"
 systrace="linux_systrace_args.c"
+compat_set=""
diff --git a/sys/i386/linux/syscalls.conf b/sys/i386/linux/syscalls.conf
--- a/sys/i386/linux/syscalls.conf
+++ b/sys/i386/linux/syscalls.conf
@@ -9,3 +9,4 @@
 switchname="linux_sysent"
 namesname="linux_syscallnames"
 systrace="linux_systrace_args.c"
+compat_set=""
diff --git a/sys/tools/makesyscalls.lua b/sys/tools/makesyscalls.lua
--- a/sys/tools/makesyscalls.lua
+++ b/sys/tools/makesyscalls.lua
@@ -56,6 +56,7 @@
 	systrace = "systrace_args.c",
 	capabilities_conf = "capabilities.conf",
 	capenabled = {},
+	compat_set = "native",
 	mincompat = 0,
 	abi_type_suffix = "",
 	abi_flags = "",
@@ -201,7 +202,7 @@
 	-- Compat flags start from here.  We have plenty of space.
 }
 
--- All compat_options entries should have five entries:
+-- All compat option entries should have five entries:
 --	definition: The preprocessor macro that will be set for this
 --	compatlevel: The level this compatibility should be included at.  This
 --	    generally represents the version of FreeBSD that it is compatible
@@ -212,23 +213,28 @@
 --	    used as-is, without "_" or any other character appended.
 --	descr: The description of this compat option in init_sysent.c comments.
 -- The special "stdcompat" entry will cause the other five to be autogenerated.
-local compat_options = {
-	{
-		definition = "COMPAT_43",
-		compatlevel = 3,
-		flag = "COMPAT",
-		prefix = "o",
-		descr = "old",
+local compat_option_sets = {
+	native = {
+		{
+			definition = "COMPAT_43",
+			compatlevel = 3,
+			flag = "COMPAT",
+			prefix = "o",
+			descr = "old",
+		},
+		{ stdcompat = "FREEBSD4" },
+		{ stdcompat = "FREEBSD6" },
+		{ stdcompat = "FREEBSD7" },
+		{ stdcompat = "FREEBSD10" },
+		{ stdcompat = "FREEBSD11" },
+		{ stdcompat = "FREEBSD12" },
+		{ stdcompat = "FREEBSD13" },
 	},
-	{ stdcompat = "FREEBSD4" },
-	{ stdcompat = "FREEBSD6" },
-	{ stdcompat = "FREEBSD7" },
-	{ stdcompat = "FREEBSD10" },
-	{ stdcompat = "FREEBSD11" },
-	{ stdcompat = "FREEBSD12" },
-	{ stdcompat = "FREEBSD13" },
 }
 
+-- compat_options will be resolved to a set from the configuration.
+local compat_options
+
 local function trim(s, char)
 	if s == nil then
 		return nil
@@ -250,7 +256,7 @@
 	-- Alternatively, we could drop the whitespace and instead try to
 	-- use a pattern to strip out the meaty part of the line, but then we
 	-- would need to sanitize the line for potentially special characters.
-	local line_expr = "^([%w%p]+%s*)=(%s*[`\"]?[^\"`]+[`\"]?)"
+	local line_expr = "^([%w%p]+%s*)=(%s*[`\"]?[^\"`]*[`\"]?)"
 
 	if not file then
 		return nil, "No file given"
@@ -1336,6 +1342,17 @@
 	end
 end
 
+local compat_set = config['compat_set']
+if compat_set ~= "" then
+	if not compat_option_sets[compat_set] then
+		abort(1, "Undefined compat set: " .. compat_set)
+	end
+
+	compat_options = compat_option_sets[compat_set]
+else
+	compat_options = {}
+end
+
 -- We ignore errors here if we're relying on the default configuration.
 if not config_modified["capenabled"] then
 	config["capenabled"] = grab_capenabled(config['capabilities_conf'],