diff --git a/DMRTrellis.cpp b/DMRTrellis.cpp
index f0a73cb..cdf30ed 100644
--- a/DMRTrellis.cpp
+++ b/DMRTrellis.cpp
@@ -280,12 +280,12 @@ void CDMRTrellis::pointsToDibits(const unsigned char* points, signed char* dibit
 void CDMRTrellis::bitsToTribits(const unsigned char* payload, unsigned char* tribits) const
 {
 	for (unsigned int i = 0U; i < 48U; i++) {
-		unsigned int n = 143U - i * 3U;
+		unsigned int n = i * 3U;
 
 		bool b1 = READ_BIT(payload, n) != 0x00U;
-		n--;
+		n++;
 		bool b2 = READ_BIT(payload, n) != 0x00U;
-		n--;
+		n++;
 		bool b3 = READ_BIT(payload, n) != 0x00U;
 
 		unsigned char tribit = 0U;
@@ -308,12 +308,12 @@ void CDMRTrellis::tribitsToBits(const unsigned char* tribits, unsigned char* pay
 		bool b2 = (tribit & 0x02U) == 0x02U;
 		bool b3 = (tribit & 0x01U) == 0x01U;
 
-		unsigned int n = 143U - i * 3U;
+		unsigned int n = i * 3U;
 
 		WRITE_BIT(payload, n, b1);
-		n--;
+		n++;
 		WRITE_BIT(payload, n, b2);
-		n--;
+		n++;
 		WRITE_BIT(payload, n, b3);
 	}
 }