diff --git a/src/x86_64-fma/common.py b/src/x86_64-fma/common.py
index ab81e4e7..b09a0d1f 100644
--- a/src/x86_64-fma/common.py
+++ b/src/x86_64-fma/common.py
@@ -116,7 +116,7 @@ def butterfly(a, b, negate_a=False, negate_b=False, scale_a=None, scale_b=None,
             VFMSUB132PS(ymm_a, ymm_b, scale_a)
             VFMADD132PS(ymm_a_copy, ymm_b, scale_a)
         elif negate_a and not negate_b:
-            VFMMADD132PS(ymm_a, ymm_b, scale_a)
+            VFMADD132PS(ymm_a, ymm_b, scale_a)
             VFNMSUB132PS(ymm_a_copy, ymm_b, scale_a)
         elif negate_a and negate_b:
             VFNMSUB132PS(ymm_a, ymm_b, scale_a)