diff --git a/tools/topology/sof/pipe-amp-ref-capture.m4 b/tools/topology/sof/pipe-amp-ref-capture.m4
index c5ff324c7..1ade59786 100644
--- a/tools/topology/sof/pipe-amp-ref-capture.m4
+++ b/tools/topology/sof/pipe-amp-ref-capture.m4
@@ -43,7 +43,7 @@ ifelse(SMART_FB_CHANNELS, `8',
 `define(`FB_CHMAP',`0x01,0x02,0x04,0x08,0x00,0x00,0x00,0x00')'
 )
 
-ifelse(SMART_REF_CHANNELS, `8',
+ifelse(SMART_REF_CH_NUM, `4',
 `define(`REF_CHMAP',`0x01,0x02,0x04,0x08,0x00,0x00,0x00,0x00')',
 `define(`REF_CHMAP',`0x01,0x04,0x00,0x00,0x00,0x00,0x00,0x00')'
 )