diff --git a/Sources/hylo-lsp-server/hylo-lsp-server-cli.swift b/Sources/hylo-lsp-server/hylo-lsp-server-cli.swift
index b7fe207..79ea473 100644
--- a/Sources/hylo-lsp-server/hylo-lsp-server-cli.swift
+++ b/Sources/hylo-lsp-server/hylo-lsp-server-cli.swift
@@ -98,8 +98,13 @@ struct HyloLspCommand: AsyncParsableCommand {
 
         #if !os(Windows)
         // Force line buffering
-        setvbuf(stdout, nil, _IOLBF, 0)
-        setvbuf(stderr, nil, _IOLBF, 0)
+        _ = withUnsafeMutablePointer(to: &stdout) { stdoutPointer in
+            setvbuf(stdoutPointer.pointee, nil, _IOLBF, 0)
+        }
+
+        _ = withUnsafeMutablePointer(to: &stderr) { stderrPointer in
+            setvbuf(stderrPointer.pointee, nil, _IOLBF, 0)
+        }
         #endif
 
         let logFileURL = URL(fileURLWithPath: logFile)