diff --git a/Source/LDSwiftEventSource.swift b/Source/LDSwiftEventSource.swift
index 1225e5b..cd10eb7 100644
--- a/Source/LDSwiftEventSource.swift
+++ b/Source/LDSwiftEventSource.swift
@@ -298,7 +298,8 @@ class EventSourceDelegate: NSObject, URLSessionDataDelegate {
 
         readyState = .closed
         let sleep = reconnectionTimer.reconnectDelay(baseDelay: currentRetry)
-        logger.log(.info, "Waiting %.3f seconds before reconnecting...", sleep)
+        // this formatting shenanigans is to workaround String not implementing CVarArg on Swift<5.4 on Linux
+        logger.log(.info, "Waiting %@ seconds before reconnecting...", String(format: "%.3f", sleep))
         delegateQueue.asyncAfter(deadline: .now() + sleep) { [weak self] in
             self?.connect()
         }
@@ -326,7 +327,8 @@ class EventSourceDelegate: NSObject, URLSessionDataDelegate {
             config.handler.onOpened()
             completionHandler(.allow)
         } else {
-            logger.log(.info, "Unsuccessful response: %d", statusCode)
+            // this formatting shenanigans is to workaround String not implementing CVarArg on Swift<5.4 on Linux
+            logger.log(.info, "Unsuccessful response: %@", String(format: "%d", statusCode))
             if dispatchError(error: UnsuccessfulResponseError(responseCode: statusCode)) == .shutdown {
                 logger.log(.info, "Connection has been explicitly shut down by error handler")
                 readyState = .shutdown
diff --git a/Source/Logs.swift b/Source/Logs.swift
index 46d62bd..9a384f0 100644
--- a/Source/Logs.swift
+++ b/Source/Logs.swift
@@ -6,8 +6,8 @@ import os.log
 
 protocol InternalLogging {
     func log(_ level: Level, _ staticMsg: StaticString)
-    func log(_ level: Level, _ staticMsg: StaticString, _ arg: CVarArg)
-    func log(_ level: Level, _ staticMsg: StaticString, _ arg1: CVarArg, _ arg2: CVarArg)
+    func log(_ level: Level, _ staticMsg: StaticString, _ arg: String)
+    func log(_ level: Level, _ staticMsg: StaticString, _ arg1: String, _ arg2: String)
 }
 
 enum Level {
@@ -35,11 +35,11 @@ class OSLogAdapter: InternalLogging {
         os_log(staticMsg, log: self.osLog, type: level.osLogType)
     }
     
-    func log(_ level: Level, _ staticMsg: StaticString, _ arg: CVarArg) {
+    func log(_ level: Level, _ staticMsg: StaticString, _ arg: String) {
         os_log(staticMsg, log: self.osLog, type: level.osLogType, arg)
     }
     
-    func log(_ level: Level, _ staticMsg: StaticString, _ arg1: CVarArg, _ arg2: CVarArg) {
+    func log(_ level: Level, _ staticMsg: StaticString, _ arg1: String, _ arg2: String) {
         os_log(staticMsg, log: self.osLog, type: level.osLogType, arg1, arg2)
     }
 }
@@ -47,6 +47,6 @@ class OSLogAdapter: InternalLogging {
 
 class NoOpLogging: InternalLogging {
     func log(_ level: Level, _ staticMsg: StaticString) {}
-    func log(_ level: Level, _ staticMsg: StaticString, _ arg: CVarArg) {}
-    func log(_ level: Level, _ staticMsg: StaticString, _ arg1: CVarArg, _ arg2: CVarArg) {}
+    func log(_ level: Level, _ staticMsg: StaticString, _ arg: String) {}
+    func log(_ level: Level, _ staticMsg: StaticString, _ arg1: String, _ arg2: String) {}
 }