diff --git a/Sources/SwiftProtobuf/NameMap.swift b/Sources/SwiftProtobuf/NameMap.swift
index f2822e893..14cbf148d 100644
--- a/Sources/SwiftProtobuf/NameMap.swift
+++ b/Sources/SwiftProtobuf/NameMap.swift
@@ -43,12 +43,8 @@ fileprivate class InternPool {
   private var interned = [UnsafeRawBufferPointer]()
 
   func intern(utf8: String.UTF8View) -> UnsafeRawBufferPointer {
-    #if swift(>=4.1)
     let mutable = UnsafeMutableRawBufferPointer.allocate(byteCount: utf8.count,
                                                          alignment: MemoryLayout<UInt8>.alignment)
-    #else
-    let mutable = UnsafeMutableRawBufferPointer.allocate(count: utf8.count)
-    #endif
     mutable.copyBytes(from: utf8)
     let immutable = UnsafeRawBufferPointer(mutable)
     interned.append(immutable)
@@ -56,12 +52,8 @@ fileprivate class InternPool {
   }
 
   func intern(utf8Ptr: UnsafeBufferPointer<UInt8>) -> UnsafeRawBufferPointer {
-    #if swift(>=4.1)
     let mutable = UnsafeMutableRawBufferPointer.allocate(byteCount: utf8Ptr.count,
                                                          alignment: MemoryLayout<UInt8>.alignment)
-    #else
-    let mutable = UnsafeMutableRawBufferPointer.allocate(count: utf8.count)
-    #endif
     mutable.copyBytes(from: utf8Ptr)
     let immutable = UnsafeRawBufferPointer(mutable)
     interned.append(immutable)
@@ -70,12 +62,7 @@ fileprivate class InternPool {
 
   deinit {
     for buff in interned {
-        #if swift(>=4.1)
-          buff.deallocate()
-        #else
-          let p = UnsafeMutableRawPointer(mutating: buff.baseAddress)!
-          p.deallocate(bytes: buff.count, alignedTo: 1)
-        #endif
+        buff.deallocate()
     }
   }
 }
diff --git a/Tests/SwiftProtobufTests/Test_JSON.swift b/Tests/SwiftProtobufTests/Test_JSON.swift
index e0b7c013d..1f533fd9a 100644
--- a/Tests/SwiftProtobufTests/Test_JSON.swift
+++ b/Tests/SwiftProtobufTests/Test_JSON.swift
@@ -655,10 +655,6 @@ class Test_JSON: XCTestCase, PBTestHelpers {
     }
 
     func testOptionalString_controlCharacters() {
-        // This is known to fail on Swift Linux 4.1 and earlier,
-        // so skip it there.
-        // See https://bugs.swift.org/browse/SR-4218 for details.
-#if !os(Linux) || swift(>=4.2)
         // Verify that all C0 controls are correctly escaped
         assertJSONEncode("{\"optionalString\":\"\\u0000\\u0001\\u0002\\u0003\\u0004\\u0005\\u0006\\u0007\"}") {(o: inout MessageTestType) in
             o.optionalString = "\u{00}\u{01}\u{02}\u{03}\u{04}\u{05}\u{06}\u{07}"
@@ -672,7 +668,6 @@ class Test_JSON: XCTestCase, PBTestHelpers {
         assertJSONEncode("{\"optionalString\":\"\\u0018\\u0019\\u001A\\u001B\\u001C\\u001D\\u001E\\u001F\"}") {(o: inout MessageTestType) in
             o.optionalString = "\u{18}\u{19}\u{1a}\u{1b}\u{1c}\u{1d}\u{1e}\u{1f}"
         }
-#endif
     }
 
     func testOptionalBytes() throws {
diff --git a/Tests/SwiftProtobufTests/Test_TextFormat_proto3.swift b/Tests/SwiftProtobufTests/Test_TextFormat_proto3.swift
index 149965cff..8e98d51bf 100644
--- a/Tests/SwiftProtobufTests/Test_TextFormat_proto3.swift
+++ b/Tests/SwiftProtobufTests/Test_TextFormat_proto3.swift
@@ -655,10 +655,6 @@ class Test_TextFormat_proto3: XCTestCase, PBTestHelpers {
     }
 
     func testEncoding_optionalString_controlCharacters() throws {
-        // This is known to fail on Swift Linux 4.1 and earlier,
-        // so skip it there.
-        // See https://bugs.swift.org/browse/SR-4218 for details.
-#if !os(Linux) || swift(>=4.2)
         assertTextFormatEncode("optional_string: \"\\001\\002\\003\\004\\005\\006\\007\"\n") {
             (o: inout MessageTestType) in
             o.optionalString = "\u{01}\u{02}\u{03}\u{04}\u{05}\u{06}\u{07}"
@@ -675,7 +671,6 @@ class Test_TextFormat_proto3: XCTestCase, PBTestHelpers {
             (o: inout MessageTestType) in
             o.optionalString = "\u{18}\u{19}\u{1a}\u{1b}\u{1c}\u{1d}\u{1e}\u{1f}"
         }
-#endif
     }
 
     func testEncoding_optionalString_UTF8() throws {