diff --git a/codecs/gsm/src/long_term.c b/codecs/gsm/src/long_term.c
index 50594ffd71..83b6fdf857 100644
--- a/codecs/gsm/src/long_term.c
+++ b/codecs/gsm/src/long_term.c
@@ -162,7 +162,10 @@ static void Calculation_of_the_LTP_parameters P4((d,dp,bc_out,Nc_out),
 	word		* Nc_out	/* 		OUT	*/
 )
 {
-	register int  	k, lambda;
+	register int  	k;
+#ifndef K6OPT
+	register int lambda;
+#endif
 	word		Nc, bc;
 	word		wt[40];
 
diff --git a/codecs/gsm/src/lpc.c b/codecs/gsm/src/lpc.c
index 49145f86e1..744149e02c 100644
--- a/codecs/gsm/src/lpc.c
+++ b/codecs/gsm/src/lpc.c
@@ -35,9 +35,12 @@ static void Autocorrelation P2((s, L_ACF),
  *  be scaled in order to avoid an overflow situation.
  */
 {
+#ifndef K6OPT
 	register int	k, i;
+	word temp;
+#endif
 
-	word		temp, smax, scalauto;
+	word		smax, scalauto;
 
 #ifdef	USE_FLOAT_MUL
 	float		float_s[160];