diff --git a/vlib/v/ast/comptime_valid_idents.v b/vlib/v/ast/comptime_valid_idents.v
index dac7d9e9330079..8d52d51dfef192 100644
--- a/vlib/v/ast/comptime_valid_idents.v
+++ b/vlib/v/ast/comptime_valid_idents.v
@@ -10,7 +10,7 @@ pub const valid_comptime_if_cpu_features = ['x64', 'x32', 'little_endian', 'big_
 pub const valid_comptime_if_other = ['apk', 'js', 'debug', 'prod', 'test', 'glibc', 'prealloc',
 	'no_bounds_checking', 'freestanding', 'threads', 'js_node', 'js_browser', 'js_freestanding',
 	'interpreter', 'es5', 'profile', 'wasm32', 'wasm32_emscripten', 'wasm32_wasi', 'fast_math',
-	'native']
+	'native', 'autofree']
 pub const valid_comptime_not_user_defined = all_valid_comptime_idents()
 pub const valid_comptime_compression_types = ['none', 'zlib']
 
diff --git a/vlib/v/checker/comptime.v b/vlib/v/checker/comptime.v
index 1b4ea929bc0f48..e8ffceb5e21bb8 100644
--- a/vlib/v/checker/comptime.v
+++ b/vlib/v/checker/comptime.v
@@ -919,6 +919,9 @@ fn (mut c Checker) comptime_if_branch(mut cond ast.Expr, pos token.Pos) Comptime
 					'no_bounds_checking' {
 						return if cname in c.pref.compile_defines_all { .eval } else { .skip }
 					}
+					'autofree' {
+						return if c.pref.autofree { .eval } else { .skip }
+					}
 					'freestanding' {
 						return if c.pref.is_bare && !c.pref.output_cross_c { .eval } else { .skip }
 					}
diff --git a/vlib/v/gen/c/comptime.v b/vlib/v/gen/c/comptime.v
index f3256b104296c1..ff09847e2344c4 100644
--- a/vlib/v/gen/c/comptime.v
+++ b/vlib/v/gen/c/comptime.v
@@ -1098,6 +1098,9 @@ fn (mut g Gen) comptime_if_to_ifdef(name string, is_comptime_option bool) !strin
 		'freestanding' {
 			return '_VFREESTANDING'
 		}
+		'autofree' {
+			return '_VAUTOFREE'
+		}
 		// architectures:
 		'amd64' {
 			return '__V_amd64'
diff --git a/vlib/v/gen/js/comptime.v b/vlib/v/gen/js/comptime.v
index 012bfba034f853..76a32cb989fd28 100644
--- a/vlib/v/gen/js/comptime.v
+++ b/vlib/v/gen/js/comptime.v
@@ -286,6 +286,9 @@ fn (mut g JsGen) comptime_if_to_ifdef(name string, is_comptime_option bool) !str
 		'freestanding' {
 			return '_VFREESTANDING'
 		}
+		'autofree' {
+			return '_VAUTOFREE'
+		}
 		// architectures:
 		'amd64' {
 			return '(\$process.arch == "x64")'