diff --git a/repos/base/include/log_session/log_session.h b/repos/base/include/log_session/log_session.h
index 45fe8460de..0a57d69e4f 100644
--- a/repos/base/include/log_session/log_session.h
+++ b/repos/base/include/log_session/log_session.h
@@ -28,7 +28,10 @@ struct Genode::Log_session : Session
 
 	virtual ~Log_session() { }
 
-	typedef Rpc_in_buffer<256> String;
+	/* the lowest platform-specific maximum IPC payload size (OKL4) */
+	enum { MAX_STRING_LEN = 236};
+
+	typedef Rpc_in_buffer<MAX_STRING_LEN> String;
 
 	/**
 	 * Output null-terminated string
diff --git a/repos/base/src/base/console/log_console.cc b/repos/base/src/base/console/log_console.cc
index e14c7d7ab4..b4271a5b5a 100644
--- a/repos/base/src/base/console/log_console.cc
+++ b/repos/base/src/base/console/log_console.cc
@@ -27,7 +27,7 @@ class Log_console : public Console
 {
 	private:
 
-		enum { _BUF_SIZE = 216 };
+		enum { _BUF_SIZE = Log_session::MAX_STRING_LEN };
 
 		Log_connection _log;
 		char           _buf[_BUF_SIZE];
diff --git a/repos/os/include/vfs/log_file_system.h b/repos/os/include/vfs/log_file_system.h
index 405a46d826..656c389137 100644
--- a/repos/os/include/vfs/log_file_system.h
+++ b/repos/os/include/vfs/log_file_system.h
@@ -47,7 +47,7 @@ class Vfs::Log_file_system : public Single_file_system
 
 			/* count does not include the trailing '\0' */
 			while (count > 0) {
-				char tmp[256];
+				char tmp[Genode::Log_session::MAX_STRING_LEN];
 				int const curr_count = min(count, sizeof(tmp) - 1);
 				memcpy(tmp, src, curr_count);
 				tmp[curr_count > 0 ? curr_count : 0] = 0;