diff --git a/Sources/_StringProcessing/PrintAsPattern.swift b/Sources/_StringProcessing/PrintAsPattern.swift
index 953df6882..61eb54ca8 100644
--- a/Sources/_StringProcessing/PrintAsPattern.swift
+++ b/Sources/_StringProcessing/PrintAsPattern.swift
@@ -518,6 +518,14 @@ extension PrettyPrinter {
         } else {
           output(base.0)
         }
+
+      case let .characterClass(cc):
+        if wrap {
+          output("One(\(cc._patternBase))")
+        } else {
+          output(cc._patternBase)
+        }
+
       default:
         print(" // TODO: Atom \(a)")
       }
diff --git a/Tests/RegexTests/RenderDSLTests.swift b/Tests/RegexTests/RenderDSLTests.swift
index c38ff0663..fbfbee616 100644
--- a/Tests/RegexTests/RenderDSLTests.swift
+++ b/Tests/RegexTests/RenderDSLTests.swift
@@ -276,4 +276,40 @@ extension RenderDSLTests {
       }
       """#)
   }
+
+  func testCharacterClass() throws {
+    try testConversion(#"[abc]+"#, #"""
+      Regex {
+        OneOrMore(.anyOf("abc"))
+      }
+      """#)
+
+    try testConversion(#"[[:whitespace:]]"#, #"""
+      Regex {
+        One(.whitespace)
+      }
+      """#)
+
+    try testConversion(#"[\b\w]+"#, #"""
+      Regex {
+        OneOrMore {
+          CharacterClass(
+            .anyOf("\u{8}"),
+            .word
+          )
+        }
+      }
+      """#)
+
+    try testConversion(#"[abc\sd]+"#, #"""
+      Regex {
+        OneOrMore {
+          CharacterClass(
+            .anyOf("abcd"),
+            .whitespace
+          )
+        }
+      }
+      """#)
+  }
 }