diff --git a/Sources/Foundation/FileHandle.swift b/Sources/Foundation/FileHandle.swift
index 72ab09a3f6..af0bfa40eb 100644
--- a/Sources/Foundation/FileHandle.swift
+++ b/Sources/Foundation/FileHandle.swift
@@ -321,10 +321,15 @@ open class FileHandle : NSObject {
             if options.contains(.alwaysMapped) {
                 // Filesizes are often 64bit even on 32bit systems
                 let mapSize = min(length, Int(clamping: statbuf.st_size))
+              #if canImport(Android)
+                // Bionic mmap() now returns _Nonnull, so the force unwrap below isn't needed.
                 let data = mmap(nil, mapSize, PROT_READ, MAP_PRIVATE, _fd, 0)
+              #else
+                let data = mmap(nil, mapSize, PROT_READ, MAP_PRIVATE, _fd, 0)!
+              #endif
                 // Swift does not currently expose MAP_FAILURE
                 if data != UnsafeMutableRawPointer(bitPattern: -1) {
-                    return NSData.NSDataReadResult(bytes: data!, length: mapSize) { buffer, length in
+                    return NSData.NSDataReadResult(bytes: data, length: mapSize) { buffer, length in
                         munmap(buffer, length)
                     }
                 }
diff --git a/Sources/Foundation/FileManager+POSIX.swift b/Sources/Foundation/FileManager+POSIX.swift
index 73d8171832..9ec12c680a 100644
--- a/Sources/Foundation/FileManager+POSIX.swift
+++ b/Sources/Foundation/FileManager+POSIX.swift
@@ -812,8 +812,8 @@ extension FileManager {
                         fts_close(stream)
                     }
 
-                    while let current = fts_read(stream)?.pointee {
-                        let itemPath = string(withFileSystemRepresentation: current.fts_path, length: Int(current.fts_pathlen))
+                    while let current = fts_read(stream)?.pointee, let current_path = current.fts_path {
+                        let itemPath = string(withFileSystemRepresentation: current_path, length: Int(current.fts_pathlen))
                         guard alreadyConfirmed || shouldRemoveItemAtPath(itemPath, isURL: isURL) else {
                             continue
                         }
@@ -821,11 +821,11 @@ extension FileManager {
                         do {
                             switch Int32(current.fts_info) {
                             case FTS_DEFAULT, FTS_F, FTS_NSOK, FTS_SL, FTS_SLNONE:
-                                if unlink(current.fts_path) == -1 {
+                                if unlink(current_path) == -1 {
                                     throw _NSErrorWithErrno(errno, reading: false, path: itemPath)
                                 }
                             case FTS_DP:
-                                if rmdir(current.fts_path) == -1 {
+                                if rmdir(current_path) == -1 {
                                     throw _NSErrorWithErrno(errno, reading: false, path: itemPath)
                                 }
                             case FTS_DNR, FTS_ERR, FTS_NS:
@@ -1217,14 +1217,14 @@ extension FileManager {
                 }
 
                 _current = fts_read(stream)
-                while let current = _current {
-                    let filename = FileManager.default.string(withFileSystemRepresentation: current.pointee.fts_path, length: Int(current.pointee.fts_pathlen))
+                while let current = _current, let current_path = current.pointee.fts_path {
+                    let filename = FileManager.default.string(withFileSystemRepresentation: current_path, length: Int(current.pointee.fts_pathlen))
 
                     switch Int32(current.pointee.fts_info) {
                         case FTS_D:
                             let (showFile, skipDescendants) = match(filename: filename, to: _options, isDir: true)
                             if skipDescendants {
-                                fts_set(_stream, _current, FTS_SKIP)
+                                fts_set(stream, current, FTS_SKIP)
                             }
                             if showFile {
                                  return URL(fileURLWithPath: filename, isDirectory: true)
diff --git a/Sources/Foundation/FileManager.swift b/Sources/Foundation/FileManager.swift
index fdd8411511..a3e9146f9b 100644
--- a/Sources/Foundation/FileManager.swift
+++ b/Sources/Foundation/FileManager.swift
@@ -579,13 +579,13 @@ open class FileManager : NSObject {
 #elseif os(WASI)
         let type = FileAttributeType(statMode: mode_t(s.st_mode))
 #else
-        if let pwd = getpwuid(s.st_uid), pwd.pointee.pw_name != nil {
-            let name = String(cString: pwd.pointee.pw_name)
+        if let pwd = getpwuid(s.st_uid), let pwd_name = pwd.pointee.pw_name {
+            let name = String(cString: pwd_name)
             result[.ownerAccountName] = name
         }
 
-        if let grd = getgrgid(s.st_gid), grd.pointee.gr_name != nil {
-            let name = String(cString: grd.pointee.gr_name)
+        if let grd = getgrgid(s.st_gid), let grd_name = grd.pointee.gr_name {
+            let name = String(cString: grd_name)
             result[.groupOwnerAccountName] = name
         }
 
diff --git a/Tests/Foundation/Tests/TestFileHandle.swift b/Tests/Foundation/Tests/TestFileHandle.swift
index 5416c41c4e..91e1bdc0ac 100644
--- a/Tests/Foundation/Tests/TestFileHandle.swift
+++ b/Tests/Foundation/Tests/TestFileHandle.swift
@@ -111,7 +111,7 @@ class TestFileHandle : XCTestCase {
 #else
         var fds: [Int32] = [-1, -1]
         fds.withUnsafeMutableBufferPointer { (pointer) -> Void in
-            pipe(pointer.baseAddress)
+            pipe(pointer.baseAddress!)
         }
         
         close(fds[1])
diff --git a/Tests/Foundation/Tests/TestTimeZone.swift b/Tests/Foundation/Tests/TestTimeZone.swift
index 5e15c00026..373e21b263 100644
--- a/Tests/Foundation/Tests/TestTimeZone.swift
+++ b/Tests/Foundation/Tests/TestTimeZone.swift
@@ -160,7 +160,7 @@ class TestTimeZone: XCTestCase {
         var lt = tm()
         localtime_r(&t, &lt)
         let zoneName = NSTimeZone.system.abbreviation() ?? "Invalid Abbreviation"
-        let expectedName = String(cString: lt.tm_zone, encoding: .ascii) ?? "Invalid Zone"
+        let expectedName = String(cString: lt.tm_zone!, encoding: .ascii) ?? "Invalid Zone"
         XCTAssertEqual(zoneName, expectedName, "expected name \"\(expectedName)\" is not equal to \"\(zoneName)\"")
     }
 #endif