diff --git a/MagickCore/effect.c b/MagickCore/effect.c
index ce837f5..c51c6f9 100644
--- a/MagickCore/effect.c
+++ b/MagickCore/effect.c
@@ -3122,8 +3122,8 @@
(void) ResetMagickMemory(kernel_info,0,sizeof(*kernel_info));
kernel_info->width=width;
kernel_info->height=width;
- kernel_info->x=(ssize_t) width/2;
- kernel_info->y=(ssize_t) width/2;
+ kernel_info->x=(ssize_t) (width-1)/2;
+ kernel_info->y=(ssize_t) (width-1)/2;
kernel_info->signature=MagickSignature;
kernel_info->values=(MagickRealType *) MagickAssumeAligned(
AcquireAlignedMemory(kernel_info->width,kernel_info->width*
