diff --git a/rpcs3/Emu/SysCalls/Modules/cellGcmSys.cpp b/rpcs3/Emu/SysCalls/Modules/cellGcmSys.cpp
index 877075b86f..d90e4a3705 100644
--- a/rpcs3/Emu/SysCalls/Modules/cellGcmSys.cpp
+++ b/rpcs3/Emu/SysCalls/Modules/cellGcmSys.cpp
@@ -701,7 +701,7 @@ int32_t cellGcmMapLocalMemory(u64 address, u64 size)
 	}
 	else
 	{
-		printf("RSX local memory already mapped");
+		cellGcmSys.Error("RSX local memory already mapped");
 		return CELL_GCM_ERROR_FAILURE;
 	}
 
diff --git a/rpcs3/Emu/SysCalls/Modules/sys_fs.cpp b/rpcs3/Emu/SysCalls/Modules/sys_fs.cpp
index a76a583acc..f37f2f1723 100644
--- a/rpcs3/Emu/SysCalls/Modules/sys_fs.cpp
+++ b/rpcs3/Emu/SysCalls/Modules/sys_fs.cpp
@@ -50,9 +50,10 @@ int sdata_unpack(wxString packed_file, wxString unpacked_file)
 
 	char buffer [10200];
 	packed_stream->Read(buffer, 256);
-	if (re32(*(u32*)&buffer[0]) != 0x4E504400) // "NPD\x00"
+	u32 format = re32(*(u32*)&buffer[0]);
+	if (format != 0x4E504400) // "NPD\x00"
 	{
-		printf("ERROR: illegal format.");
+		sys_fs.Error("Illegal format. Expected 0x4E504400, but got 0x%08x", format);
 		return CELL_EFSSPECIFIC;
 	}