--- src/short_term.c	(libgsm 1.0.10)
+++ src/short_term.c	(libgsm 1.0.17)
@@ -53,5 +53,5 @@
 #undef	STEP
-#define	STEP( B, MIC, INVA )	\
+#define	STEP( B_TIMES_TWO, MIC, INVA )	\
 		temp1    = GSM_ADD( *LARc++, MIC ) << 10;	\
-		temp1    = GSM_SUB( temp1, B << 1 );		\
+		temp1    = GSM_SUB( temp1, B_TIMES_TWO );	\
 		temp1    = GSM_MULT_R( INVA, temp1 );		\
@@ -61,9 +61,9 @@
 	STEP(      0,  -32,  13107 );
-	STEP(   2048,  -16,  13107 );
-	STEP(  -2560,  -16,  13107 );
+	STEP(   4096,  -16,  13107 );
+	STEP(  -5120,  -16,  13107 );
 
-	STEP(     94,   -8,  19223 );
-	STEP(  -1792,   -8,  17476 );
-	STEP(   -341,   -4,  31454 );
-	STEP(  -1144,   -4,  29708 );
+	STEP(    188,   -8,  19223 );
+	STEP(  -3584,   -8,  17476 );
+	STEP(   -682,   -4,  31454 );
+	STEP(  -2288,   -4,  29708 );