diff --git a/README.md b/README.md
index 8e15909..85bce6f 100644
--- a/README.md
+++ b/README.md
@@ -17,13 +17,13 @@ Just replace `http.ListenAndServe` with `anyhttp.ListenAndServe`.
 
 Syntax
 
-    unix?path=<socket_path>&mode=<socket file mode>&remove_existing=<yes|no>
+    unix?path=<socket_path>&mode=<socket file mode>&remove_existing=<true|false>
 
 Examples
 
     unix?path=relative/path.sock
     unix?path=/var/run/app/absolutepath.sock
-    unix?path=/run/app.sock&mode=600&remove_existing=no
+    unix?path=/run/app.sock&mode=600&remove_existing=false
 
 | option          | description                                    | default  |
 |-----------------|------------------------------------------------|----------|
@@ -35,7 +35,7 @@ Examples
 
 Syntax
 
-    sysd?idx=<fd index>&name=<fd name>&check_pid=<yes|no>&unset_env=<yes|no>&idle_timeout=<duration>
+    sysd?idx=<fd index>&name=<fd name>&check_pid=<true|false>&unset_env=<true|false>&idle_timeout=<duration>
 
 Only one of `idx` or `name` has to be set
 
diff --git a/anyhttp_test.go b/anyhttp_test.go
index 74f58ad..b6decaa 100644
--- a/anyhttp_test.go
+++ b/anyhttp_test.go
@@ -72,6 +72,20 @@ func Test_parseAddress(t *testing.T) {
 			wantSysc:     nil,
 			wantErr:      true,
 		},
+		{
+			name:         "systemd address with check_pid and unset_env",
+			addr:         "sysd?idx=0&check_pid=false&unset_env=f",
+			wantAddrType: SystemdFD,
+			wantUsc:      nil,
+			wantSysc: &SysdConfig{
+				FDIndex:     ptr(0),
+				FDName:      nil,
+				CheckPID:    false,
+				UnsetEnv:    false,
+				IdleTimeout: nil,
+			},
+			wantErr: false,
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {