diff --git a/ext/f2c_math/ddaspk.c b/ext/f2c_math/ddaspk.c
index 44ffb2319..052eb72cd 100644
--- a/ext/f2c_math/ddaspk.c
+++ b/ext/f2c_math/ddaspk.c
@@ -8561,7 +8561,7 @@ L30:
 	}
 	i__2 = km1;
 	for (j = 1; j <= i__2; ++j) {
-	    i__ = (j - 1 << 1) + 1;
+	    i__ = ((j - 1) << 1) + 1;
 	    t1 = a[j + k * a_dim1];
 	    t2 = a[j + 1 + k * a_dim1];
 	    c__ = q[i__];
@@ -8617,7 +8617,7 @@ L70:
 /* ----------------------------------------------------------------------- */
     i__1 = nm1;
     for (k = 1; k <= i__1; ++k) {
-	i__ = (k - 1 << 1) + 1;
+	i__ = ((k - 1) << 1) + 1;
 	t1 = a[k + *n * a_dim1];
 	t2 = a[k + 1 + *n * a_dim1];
 	c__ = q[i__];
@@ -8745,7 +8745,7 @@ L130:
     i__1 = *n;
     for (k = 1; k <= i__1; ++k) {
 	kp1 = k + 1;
-	iq = (k - 1 << 1) + 1;
+	iq = ((k - 1) << 1) + 1;
 	c__ = q[iq];
 	s = q[iq + 1];
 	t1 = b[k];