diff --git a/lib/msun/src/k_exp.c b/lib/msun/src/k_exp.c
index c6dfc953c39d..dd15ff4cb0ed 100644
--- a/lib/msun/src/k_exp.c
+++ b/lib/msun/src/k_exp.c
@@ -88,7 +88,7 @@ __ldexp_exp(double x, int expt)
 double complex
 __ldexp_cexp(double complex z, int expt)
 {
-	double x, y, exp_x, scale1, scale2;
+	double c, exp_x, s, scale1, scale2, x, y;
 	int ex_expt, half_expt;
 
 	x = creal(z);
@@ -105,6 +105,7 @@ __ldexp_cexp(double complex z, int expt)
 	half_expt = expt - half_expt;
 	INSERT_WORDS(scale2, (0x3ff + half_expt) << 20, 0);
 
-	return (CMPLX(cos(y) * exp_x * scale1 * scale2,
-	    sin(y) * exp_x * scale1 * scale2));
+	sincos(y, &s, &c);
+	return (CMPLX(c * exp_x * scale1 * scale2,
+	    s * exp_x * scale1 * scale2));
 }
diff --git a/lib/msun/src/k_expf.c b/lib/msun/src/k_expf.c
index 5b0993f9b1bd..80e629b0f3d6 100644
--- a/lib/msun/src/k_expf.c
+++ b/lib/msun/src/k_expf.c
@@ -71,7 +71,7 @@ __ldexp_expf(float x, int expt)
 float complex
 __ldexp_cexpf(float complex z, int expt)
 {
-	float x, y, exp_x, scale1, scale2;
+	float c, exp_x, s, scale1, scale2, x, y;
 	int ex_expt, half_expt;
 
 	x = crealf(z);
@@ -84,6 +84,7 @@ __ldexp_cexpf(float complex z, int expt)
 	half_expt = expt - half_expt;
 	SET_FLOAT_WORD(scale2, (0x7f + half_expt) << 23);
 
-	return (CMPLXF(cosf(y) * exp_x * scale1 * scale2,
-	    sinf(y) * exp_x * scale1 * scale2));
+	sincosf(y, &s, &c);
+	return (CMPLXF(c * exp_x * scale1 * scale2,
+	    s * exp_x * scale1 * scale2));
 }