diff --git a/rpcs3/Emu/Cell/Modules/cellVoice.cpp b/rpcs3/Emu/Cell/Modules/cellVoice.cpp
index 7c507a26a3..912ec20266 100644
--- a/rpcs3/Emu/Cell/Modules/cellVoice.cpp
+++ b/rpcs3/Emu/Cell/Modules/cellVoice.cpp
@@ -167,7 +167,7 @@ error_code cellVoiceCreatePort(vm::ptr<u32> portId, vm::cptr<CellVoicePortParam>
 		return CELL_VOICE_ERROR_ARGUMENT_INVALID;
 	}
 
-	if (manager.ports.size() > CELLVOICE_MAX_PORT)
+	if (manager.ports.size() >= CELLVOICE_MAX_PORT)
 		return CELL_VOICE_ERROR_RESOURCE_INSUFFICIENT;
 
 	// Id: bits [8,15] seem to contain a "random" value
@@ -427,6 +427,8 @@ error_code cellVoiceInitEx(vm::ptr<CellVoiceInitParam> pArg)
 
 	auto& manager = g_fxo->get<voice_manager>();
 
+	std::lock_guard lock(manager.mtx);
+
 	if (manager.is_init)
 		return CELL_VOICE_ERROR_LIBVOICE_INITIALIZED;