diff --git a/lib/fosphor/cl.c b/lib/fosphor/cl.c
index 7a119b7..8d9edbb 100644
--- a/lib/fosphor/cl.c
+++ b/lib/fosphor/cl.c
@@ -466,7 +466,7 @@ cl_do_init(struct fosphor_cl_state *cl, struct fosphor_gl_state *gl)
 	CL_ERR_CHECK(err, "Unable to create display kernel");
 
 	/* Configure static display kernel args */
-	cl_uint fft_log2_len = 10;
+	cl_uint fft_log2_len = FOSPHOR_FFT_LEN_LOG;
 	cl_uint fft_batch    = FOSPHOR_FFT_MAX_BATCH;
 	cl_float histo_t0r   = 16.0f;
 	cl_float histo_t0d   = 1024.0f;
diff --git a/lib/fosphor/config.h b/lib/fosphor/config.h
index c309b5d..fa85520 100644
--- a/lib/fosphor/config.h
+++ b/lib/fosphor/config.h
@@ -31,7 +31,8 @@
  */
 
 
-#define FOSPHOR_FFT_LEN		1024
+#define FOSPHOR_FFT_LEN_LOG	10
+#define FOSPHOR_FFT_LEN		(1<<FOSPHOR_FFT_LEN_LOG)
 #define FOSPHOR_FFT_MAX_BATCH	128