diff --git a/interface/zsyr.c b/interface/zsyr.c
index 5d62e8797..5fe29cefa 100644
--- a/interface/zsyr.c
+++ b/interface/zsyr.c
@@ -173,7 +173,7 @@ void CNAME(enum CBLAS_ORDER order, enum CBLAS_UPLO Uplo, int n, FLOAT alpha, FLO
 
   FUNCTION_PROFILE_START();
 
-  if (incx < 0 ) x -= (n - 1) * incx;
+  if (incx < 0 ) x -= (n - 1) * incx * 2;
 
   buffer = (FLOAT *)blas_memory_alloc(1);