diff --git a/src/tools/chdman.c b/src/tools/chdman.c
index 43c165f2c75..d84d4760010 100644
--- a/src/tools/chdman.c
+++ b/src/tools/chdman.c
@@ -1086,6 +1086,11 @@ static void parse_compression(const parameters_t &params, chd_codec_type compres
 		if (end == -1)
 			break;
 	}
+	
+	for(;index < 4; ++index)
+	{
+		compression[index] = CHD_CODEC_NONE;
+	}
 }