diff --git a/src/cl-blas.lisp b/src/cl-blas.lisp
index 4e8da46..366722d 100644
--- a/src/cl-blas.lisp
+++ b/src/cl-blas.lisp
@@ -90,12 +90,14 @@
 (declaim (inline simd-abs-f32.8 simd-abs-f64.4))
 
 (defun simd-abs-f32.8 (pack)
-  (declare (f32.8 pack))
-  (f32.8-sqrt (f32.8* pack pack)))
+  (declare (f32.8 pack)
+           (optimize . #.*optimize-qualities*))
+  (f32.8-if (f32.8< pack (f32.8 0.0)) (f32.8* pack (f32.8 -1.0)) pack))
 
 (defun simd-abs-f64.4 (pack)
-  (declare (f64.4 pack))
-  (f64.4-sqrt (f64.4* pack pack)))
+  (declare (f64.4 pack)
+           (optimize . #.*optimize-qualities*))
+  (f64.4-if (f64.4< pack 0) (f64.4* pack -1) pack))
 
 (push '(simd-abs simd-abs-f32.8) *single-float-fn-generic*)
 (push '(simd-abs simd-abs-f64.4) *double-float-fn-generic*)