diff --git a/src/conf/pcm/dmix.conf b/src/conf/pcm/dmix.conf
index f5de5b56..1bd3efef 100644
--- a/src/conf/pcm/dmix.conf
+++ b/src/conf/pcm/dmix.conf
@@ -38,23 +38,8 @@ pcm.!dmix {
 	}
 	type dmix
 	ipc_key {
-		@func iadd
-		integers [
-			{
-				@func refer
-				name defaults.pcm.ipc_key
-			}
-			{
-				@func imul
-				integers [
-					{
-						@func card_inum
-						$CARD
-					}
-					2
-				]
-			}
-		]
+		@func refer
+		name defaults.pcm.ipc_key
 	}
 	ipc_gid {
 		@func refer
diff --git a/src/conf/pcm/dsnoop.conf b/src/conf/pcm/dsnoop.conf
index 14a47d70..c461f0c9 100644
--- a/src/conf/pcm/dsnoop.conf
+++ b/src/conf/pcm/dsnoop.conf
@@ -38,23 +38,8 @@ pcm.!dsnoop {
 	}
 	type dsnoop
 	ipc_key {
-		@func iadd
-		integers [
-			{
-				@func refer
-				name defaults.pcm.ipc_key
-			}
-			{
-				@func imul
-				integers [
-					{
-						@func card_inum
-						$CARD
-					}
-					2
-				]
-			}
-		]
+		@func refer
+		name defaults.pcm.ipc_key
 	}	
 	ipc_gid {
 		@func refer