diff --git a/src/main/java/net/thauvin/erik/httpstatus/StatusCode.java b/src/main/java/net/thauvin/erik/httpstatus/StatusCode.java
index 1982200..46e3468 100644
--- a/src/main/java/net/thauvin/erik/httpstatus/StatusCode.java
+++ b/src/main/java/net/thauvin/erik/httpstatus/StatusCode.java
@@ -139,7 +139,7 @@ public class StatusCode implements Serializable {
      * @return <code>true</code> if the status code is valid, <code>false</code> otherwise.
      */
     public boolean isValid() {
-        return code >= 100 && code < 600;
+        return code == 783 || (code >= 100 && code < 600);
     }
 
     /**
diff --git a/src/main/resources/net/thauvin/erik/httpstatus/reasons.properties b/src/main/resources/net/thauvin/erik/httpstatus/reasons.properties
index c690ea9..a05fa40 100644
--- a/src/main/resources/net/thauvin/erik/httpstatus/reasons.properties
+++ b/src/main/resources/net/thauvin/erik/httpstatus/reasons.properties
@@ -2,6 +2,11 @@
 101=Switching Protocols
 102=Processing
 103=Early Hints
+110=Response is Stale
+111=Revalidation Failed
+112=Disconnected Operation
+113=Heuristic Expiration
+199=Miscellaneous Warning
 200=OK
 201=Created
 202=Accepted
@@ -11,15 +16,17 @@
 206=Partial Content
 207=Multi-Status
 208=Already Reported
+214=Transformation Applied
 218=This is fine
 226=IM Used
+299=Miscellaneous Persistent Warning
 300=Multiple Choices
 301=Moved Permanently
 302=Found/Moved Temporarily
 303=See Other
 304=Not Modified
 305=Use Proxy
-306=Switch Proxy
+306=Unused
 307=Temporary Redirect
 308=Permanent Redirect
 400=Bad Request
@@ -35,18 +42,19 @@
 410=Gone
 411=Length Required
 412=Precondition Failed
-413=Request Entity/Payload Too Large
-414=Request-URI Too Long
+413=Payload Too Large
+414=URI Too Long
 415=Unsupported Media Type
-416=Requested Range Not Satisfiable
+416=Range Not Satisfiable
 417=Expectation Failed
 418=I'm A Teapot
 419=Insufficient Space on Resource
 420=Method Failure
 421=Misdirected Request
-422=Unprocessable Entity
+422=Unprocessable Content
 423=Locked
 424=Failed Dependency
+425=Too Early
 426=Upgrade Required
 428=Precondition Required
 429=Too Many Requests
@@ -61,7 +69,7 @@
 463=X-Forwarded-For Header with More than 30 IP Addresses
 494=Request Header Too Large
 495=SSL Certificate Error
-496=No SSL Certificate
+496=SSL Certificate Required
 497=HTTP Request Sent to HTTPS Port
 498=Token Expired/Invalid
 499=Client Closed Request
@@ -79,7 +87,7 @@
 511=Network Authentication Required
 520=Unknown Error
 521=Web Server Is Down
-522=Origin Connection Time-out
+522=Connection Timed Out
 523=Origin Is Unreachable
 524=A Timeout Occurred
 525=SSL Handshake Failed
@@ -87,5 +95,8 @@
 527=Railgun Error
 529=Site is overloaded
 530=Site is frozen
+540=Temporarily Disabled
+561=Unauthorized
 598=Network Read Timeout Error
-599=Network Connect Timeout Error
\ No newline at end of file
+599=Network Connect Timeout Error
+783=Unexpected Token
diff --git a/src/test/java/net/thauvin/erik/httpstatus/StatusCodeTest.java b/src/test/java/net/thauvin/erik/httpstatus/StatusCodeTest.java
index 7ecd692..b494715 100644
--- a/src/test/java/net/thauvin/erik/httpstatus/StatusCodeTest.java
+++ b/src/test/java/net/thauvin/erik/httpstatus/StatusCodeTest.java
@@ -59,9 +59,9 @@ class StatusCodeTest {
             assertThat(statusCode.isClientError()).as(code + " is client error").isEqualTo(code >= 400 && code < 500);
             assertThat(statusCode.isServerError()).as(code + " is server error").isEqualTo(code >= 500 && code < 600);
             assertThat(statusCode.isError()).as(code + " is error").isEqualTo(code >= 400 && code < 600);
-            assertThat(statusCode.isValid()).as(code + "is valid").isTrue();
+            assertThat(statusCode.isValid()).as(code + " is valid").isTrue();
 
-            assertThat(statusCode.getReason()).as(code + "reason phrase is not valid")
+            assertThat(statusCode.getReason()).as(code + " reason phrase is not valid")
                     .isEqualTo(Reasons.getReasonPhrase(code));
         }
 
@@ -75,8 +75,8 @@ class StatusCodeTest {
             assertThat(statusCode.isClientError()).as(code + " is client error").isFalse();
             assertThat(statusCode.isServerError()).as(code + " is server error").isFalse();
             assertThat(statusCode.isError()).as(code + " is error").isFalse();
-            assertThat(statusCode.isValid()).as("600 is invalid").isFalse();
-            assertThat(statusCode.getReason()).as(code + "reason phrase is not null.").isNull();
+            assertThat(statusCode.isValid()).as(code + " is invalid").isFalse();
+            assertThat(statusCode.getReason()).as(code + " reason phrase is not null.").isNull();
         }
 
         statusCode = new StatusCode(900);