diff --git a/src/url-pattern-parser.ts b/src/url-pattern-parser.ts
index b5b1f41..48f33c2 100644
--- a/src/url-pattern-parser.ts
+++ b/src/url-pattern-parser.ts
@@ -60,6 +60,9 @@ export class Parser {
   // The current nest depth of `{ }` pattern groupings.
   private groupDepth: number = 0;
 
+  // The current nesting depth of `[ ]` in hostname patterns.
+  private hostnameIPv6BracketDepth: number = 0;
+
   // True if we should apply parse rules as if this is a "standard" URL.  If
   // false then this is treated as a "not a base URL".
   private shouldTreatAsStandardURL: boolean = false;
@@ -242,8 +245,16 @@ export class Parser {
           break;
 
         case State.HOSTNAME:
+          // Track whether we are inside ipv6 address brackets.
+          if (this.isIPv6Open()) {
+            this.hostnameIPv6BracketDepth += 1;
+          } else if (this.isIPv6Close()) {
+            this.hostnameIPv6BracketDepth -= 1;
+          }
+
           // If we find a `:` then we transition to the port component state.
-          if (this.isPortPrefix()) {
+          // However, we ignore `:` when parsing an ipv6 address.
+          if (this.isPortPrefix() && !this.hostnameIPv6BracketDepth) {
             this.changeState(State.PORT, /*skip=*/1);
           }
 
@@ -468,6 +479,14 @@ export class Parser {
     return this.tokenList[this.tokenIndex].type == 'CLOSE';
   }
 
+  private isIPv6Open(): boolean {
+    return this.isNonSpecialPatternChar(this.tokenIndex, '[');
+  }
+
+  private isIPv6Close(): boolean {
+    return this.isNonSpecialPatternChar(this.tokenIndex, ']');
+  }
+
   private makeComponentString(): string {
     const token: LexToken = this.tokenList[this.tokenIndex];
     const componentCharStart = this.safeToken(this.componentStart).index;
diff --git a/src/url-utils.ts b/src/url-utils.ts
index ee67e3a..ed379d3 100644
--- a/src/url-utils.ts
+++ b/src/url-utils.ts
@@ -233,7 +233,7 @@ export function hostnameEncodeCallback(input: string): string {
   if (input === '') {
     return input;
   }
-  if (/[#%/:<>?@[\]\\|]/g.test(input)) {
+  if (input[0] !== '[' && /[#%/:<>?@[\]\\|]/g.test(input)) {
     throw(new TypeError(`Invalid hostname '${input}'`));
   }
   const url = new URL('https://example.com');
diff --git a/urlpatterntestdata.json b/urlpatterntestdata.json
index 294b223..5a3eae5 100644
--- a/urlpatterntestdata.json
+++ b/urlpatterntestdata.json
@@ -2085,6 +2085,55 @@
       "pathname": { "input": "/data:channel.html", "groups": {} }
     }
   },
+  {
+    "pattern": [ "http://[\\:\\:1]/" ],
+    "inputs": [ "http://[::1]/" ],
+    "exactly_empty_components": [ "username", "password", "port", "search",
+                                  "hash" ],
+    "expected_obj": {
+      "protocol": "http",
+      "hostname": "[\\:\\:1]",
+      "pathname": "/"
+    },
+    "expected_match": {
+      "protocol": { "input": "http", "groups": {} },
+      "hostname": { "input": "[::1]", "groups": {} },
+      "pathname": { "input": "/", "groups": {} }
+    }
+  },
+  {
+    "pattern": [ "http://[\\:\\:1]:8080/" ],
+    "inputs": [ "http://[::1]:8080/" ],
+    "exactly_empty_components": [ "username", "password", "search", "hash" ],
+    "expected_obj": {
+      "protocol": "http",
+      "hostname": "[\\:\\:1]",
+      "port": "8080",
+      "pathname": "/"
+    },
+    "expected_match": {
+      "protocol": { "input": "http", "groups": {} },
+      "hostname": { "input": "[::1]", "groups": {} },
+      "port": { "input": "8080", "groups": {} },
+      "pathname": { "input": "/", "groups": {} }
+    }
+  },
+  {
+    "pattern": [ "http://[\\:\\:a]/" ],
+    "inputs": [ "http://[::a]/" ],
+    "exactly_empty_components": [ "username", "password", "port", "search",
+                                  "hash" ],
+    "expected_obj": {
+      "protocol": "http",
+      "hostname": "[\\:\\:a]",
+      "pathname": "/"
+    },
+    "expected_match": {
+      "protocol": { "input": "http", "groups": {} },
+      "hostname": { "input": "[::a]", "groups": {} },
+      "pathname": { "input": "/", "groups": {} }
+    }
+  },
   {
     "pattern": [ "https://foo{{@}}example.com" ],
     "inputs": [ "https://foo@example.com" ],