diff --git a/Transceiver52M/convert.c b/Transceiver52M/convert.c
index dc5e748..3ab670c 100644
--- a/Transceiver52M/convert.c
+++ b/Transceiver52M/convert.c
@@ -164,7 +164,7 @@ static void convert_scale_ps_si16(short *out, float *in, float scale, int len)
 }
 #endif
 
-#ifndef HAVE_SSE_4_1
+#ifndef HAVE_SSE4_1
 static void convert_si16_ps(float *out, short *in, int len)
 {
 	for (int i = 0; i < len; i++)