diff --git a/unsupported/Eigen/src/SpecialFunctions/BesselFunctionsImpl.h b/unsupported/Eigen/src/SpecialFunctions/BesselFunctionsImpl.h
index 856caafa0..a9b6ad940 100644
--- a/unsupported/Eigen/src/SpecialFunctions/BesselFunctionsImpl.h
+++ b/unsupported/Eigen/src/SpecialFunctions/BesselFunctionsImpl.h
@@ -991,7 +991,7 @@ struct generic_k1<T, float> {
         generic_i1<T, float>::run(x), plog(pmul(pset1<T>(0.5), x)), x_le_two);
     x_le_two = pselect(pcmp_le(x, pset1<T>(0.0)), MAXNUM, x_le_two);
     T x_gt_two = pmul(
-        pexp(-x),
+        pexp(pnegate(x)),
         pmul(
             internal::pchebevl<T, 10>::run(
                 psub(pdiv(pset1<T>(8.0), x), two), B),