diff --git a/src/BizHawk.Emulation.Cores/Computers/Doom/DSDA.ISettable.cs b/src/BizHawk.Emulation.Cores/Computers/Doom/DSDA.ISettable.cs
index 0a7af7f741..f3c2590fe3 100644
--- a/src/BizHawk.Emulation.Cores/Computers/Doom/DSDA.ISettable.cs
+++ b/src/BizHawk.Emulation.Cores/Computers/Doom/DSDA.ISettable.cs
@@ -345,6 +345,11 @@ namespace BizHawk.Emulation.Cores.Computers.Doom
 			[DefaultValue(false)]
 			public bool PistolStart { get; set; }
 
+			[DisplayName("Co-op Mode Spawns")]
+			[Description("Play single-player mode with co-op thing spawns.")]
+			[DefaultValue(false)]
+			public bool CoopSpawns { get; set; }
+
 			[DisplayName("Chain Episodes")]
 			[Description("Completing one episode leads to the next without interruption. Not available in vanilla.")]
 			[DefaultValue(false)]
diff --git a/src/BizHawk.Emulation.Cores/Computers/Doom/DSDA.cs b/src/BizHawk.Emulation.Cores/Computers/Doom/DSDA.cs
index 2f5d0c92f9..3eea115d0e 100644
--- a/src/BizHawk.Emulation.Cores/Computers/Doom/DSDA.cs
+++ b/src/BizHawk.Emulation.Cores/Computers/Doom/DSDA.cs
@@ -263,6 +263,7 @@ namespace BizHawk.Emulation.Cores.Computers.Doom
 			ConditionalArg(_syncSettings.MonstersRespawn, "-respawn");
 			ConditionalArg(_syncSettings.NoMonsters,      "-nomonsters");
 			ConditionalArg(_syncSettings.PistolStart,     "-pistolstart");
+			ConditionalArg(_syncSettings.CoopSpawns,      "-coop_spawns");
 			ConditionalArg(_syncSettings.ChainEpisodes,   "-chain_episodes");
 			ConditionalArg(_syncSettings.TurningResolution == TurningResolution.Longtics, "-longtics");
 			ConditionalArg(_syncSettings.MultiplayerMode   == MultiplayerMode.Deathmatch, "-deathmatch");