diff --git a/libsupport/src/URI.cpp b/libsupport/src/URI.cpp
index 97eddf85ec..1d9e4368ac 100644
--- a/libsupport/src/URI.cpp
+++ b/libsupport/src/URI.cpp
@@ -117,6 +117,9 @@ DoJoinPath(std::string_view dir, std::string_view file) {
   return fmt::format("{}{}", dir, file);
 }
 
+// As defined by https://www.rfc-editor.org/rfc/rfc3986,
+// we encode characters outside this list
+// "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._~:/?#[]@!$&'()*+,;="
 bool
 ShouldURLEncode(int c) {
   if ('a' <= c && c <= 'z') {
@@ -128,26 +131,32 @@ ShouldURLEncode(int c) {
   if ('0' <= c && c <= '9') {
     return false;
   }
-  if (c == '-') {
-    return false;
-  }
-  if (c == '.') {
-    return false;
-  }
-  if (c == '_') {
-    return false;
-  }
-  if (c == '~') {
-    return false;
-  }
-
-  // We encode whole paths, so in addition to the standard unencoded characters
-  // above, we should not encode '/' either.
-  if (c == '/') {
+  switch (c) {
+  case '-':
+  case '.':
+  case '_':
+  case '~':
+  case ':':
+  case '/':
+  case '?':
+  case '#':
+  case '[':
+  case ']':
+  case '@':
+  case '!':
+  case '$':
+  case '&':
+  case '\'':
+  case '(':
+  case ')':
+  case '*':
+  case '+':
+  case ',':
+  case ';':
     return false;
+  default:
+    return true;
   }
-
-  return true;
 }
 
 // ToHex converts a char between 0 and 15 to an ASCII character from 0 to F.
diff --git a/libsupport/test/uri.cpp b/libsupport/test/uri.cpp
index 8a025abe37..3eb4e405d9 100644
--- a/libsupport/test/uri.cpp
+++ b/libsupport/test/uri.cpp
@@ -20,6 +20,8 @@ TestMake() {
   // this
   KATANA_LOG_ASSERT(Str2Uri("s3:///some/path//").path() == "/some/path/");
   KATANA_LOG_ASSERT(Str2Uri("s3://some/path").path() == "some/path");
+  KATANA_LOG_ASSERT(
+      Str2Uri("hdfs://somehost:8020/path").path() == "somehost:8020/path");
 
   KATANA_LOG_ASSERT(Str2Uri("path").BaseName() == "path");
   KATANA_LOG_ASSERT(Str2Uri("path///////").StripSep().path() == "path");
@@ -41,6 +43,9 @@ TestJoinPath() {
       katana::Uri::JoinPath("/some/long///", "/path") == "/some/long/path");
   KATANA_LOG_ASSERT(
       katana::Uri::JoinPath("/some/long///", "//path") == "/some/long/path");
+  KATANA_LOG_ASSERT(
+      katana::Uri::JoinPath("/host:8020/long///", "//path") ==
+      "/host:8020/long/path");
 }
 
 void
@@ -66,6 +71,8 @@ TestDecode() {
 
   KATANA_LOG_ASSERT(
       katana::Uri::Decode("/%20with/%20spaces") == "/ with/ spaces");
+  KATANA_LOG_ASSERT(
+      katana::Uri::Decode("host%3A8020/path") == "host:8020/path");
 }
 
 }  // namespace