diff --git a/src/convolutional_kernels.cu b/src/convolutional_kernels.cu
index 8645fbfd..fcf24668 100644
--- a/src/convolutional_kernels.cu
+++ b/src/convolutional_kernels.cu
@@ -8,7 +8,7 @@ extern "C" {
 #include "cuda.h"
 }
 
-__global__ void bias(int n, int size, float *biases, float *output)
+__global__ void bias_output_kernel(float *output, float *biases, int n, int size)
 {
     int offset = blockIdx.x * blockDim.x + threadIdx.x;
     int filter = blockIdx.y;
@@ -17,18 +17,16 @@ __global__ void bias(int n, int size, float *biases, float *output)
     if(offset < size) output[(batch*n+filter)*size + offset] = biases[filter];
 }
 
-extern "C" void bias_output_gpu(const convolutional_layer layer)
+extern "C" void bias_output_gpu(float *output, float *biases, int batch, int n, int size)
 {
-    int size = convolutional_out_height(layer)*convolutional_out_width(layer);
-
     dim3 dimBlock(BLOCK, 1, 1);
-    dim3 dimGrid((size-1)/BLOCK + 1, layer.n, layer.batch);
+    dim3 dimGrid((size-1)/BLOCK + 1, n, batch);
 
-    bias<<<dimGrid, dimBlock>>>(layer.n, size, layer.biases_gpu, layer.output_gpu);
+    bias_output_kernel<<<dimGrid, dimBlock>>>(output, biases, n, size);
     check_error(cudaPeekAtLastError());
 }
 
-__global__ void learn_bias(int batch, int n, int size, float *delta, float *bias_updates, float scale)
+__global__ void backward_bias_kernel(float *bias_updates, float *delta, int batch, int n, int size, float scale)
 {
     __shared__ float part[BLOCK];
     int i,b;
@@ -48,36 +46,14 @@ __global__ void learn_bias(int batch, int n, int size, float *delta, float *bias
     }
 }
 
-extern "C" void learn_bias_convolutional_layer_ongpu(convolutional_layer layer)
+extern "C" void backward_bias_gpu(float *bias_updates, float *delta, int batch, int n, int size)
 {
-    int size = convolutional_out_height(layer)*convolutional_out_width(layer);
-    float alpha = 1./layer.batch;
+    float alpha = 1./batch;
 
-    learn_bias<<<layer.n, BLOCK>>>(layer.batch, layer.n, size, layer.delta_gpu, layer.bias_updates_gpu, alpha);
+    backward_bias_kernel<<<n, BLOCK>>>(bias_updates, delta, batch, n, size, alpha);
     check_error(cudaPeekAtLastError());
 }
 
-extern "C" void test_learn_bias(convolutional_layer l)
-{
-    int i;
-    int size = convolutional_out_height(l) * convolutional_out_width(l);
-    for(i = 0; i < size*l.batch*l.n; ++i){
-        l.delta[i] = rand_uniform();
-    }
-    for(i = 0; i < l.n; ++i){
-        l.bias_updates[i] = rand_uniform();
-    }
-    cuda_push_array(l.delta_gpu, l.delta, size*l.batch*l.n);
-    cuda_push_array(l.bias_updates_gpu, l.bias_updates, l.n);
-    float *gpu = (float *) calloc(l.n, sizeof(float));
-    cuda_pull_array(l.bias_updates_gpu, gpu, l.n);
-    for(i = 0; i < l.n; ++i) printf("%.9g %.9g\n", l.bias_updates[i], gpu[i]);
-    learn_bias_convolutional_layer_ongpu(l);
-    learn_bias_convolutional_layer(l);
-    cuda_pull_array(l.bias_updates_gpu, gpu, l.n);
-    for(i = 0; i < l.n; ++i) printf("%.9g %.9g\n", l.bias_updates[i], gpu[i]);
-}
-
 extern "C" void forward_convolutional_layer_gpu(convolutional_layer layer, float *in)
 {
     int i;
@@ -86,7 +62,7 @@ extern "C" void forward_convolutional_layer_gpu(convolutional_layer layer, float
     int n = convolutional_out_height(layer)*
         convolutional_out_width(layer);
 
-    bias_output_gpu(layer);
+    bias_output_gpu(layer.output_gpu, layer.biases_gpu, layer.batch, layer.n, n);
 
     for(i = 0; i < layer.batch; ++i){
         im2col_ongpu(in, i*layer.c*layer.h*layer.w, layer.c,  layer.h,  layer.w,  layer.size,  layer.stride, layer.pad, layer.col_image_gpu);
@@ -106,8 +82,9 @@ extern "C" void backward_convolutional_layer_gpu(convolutional_layer layer, floa
     int n = layer.size*layer.size*layer.c;
     int k = convolutional_out_height(layer)*
         convolutional_out_width(layer);
+
     gradient_array_ongpu(layer.output_gpu, m*k*layer.batch, layer.activation, layer.delta_gpu);
-    learn_bias_convolutional_layer_ongpu(layer);
+    backward_bias_gpu(layer.bias_updates_gpu, layer.delta_gpu, layer.batch, layer.n, k);
 
     if(delta_gpu) scal_ongpu(layer.batch*layer.h*layer.w*layer.c, 0, delta_gpu, 1);
 
diff --git a/src/convolutional_layer.c b/src/convolutional_layer.c
index 6a172aa2..2e25844f 100644
--- a/src/convolutional_layer.c
+++ b/src/convolutional_layer.c
@@ -111,27 +111,37 @@ void resize_convolutional_layer(convolutional_layer *layer, int h, int w, int c)
                                 layer->batch*out_h * out_w * layer->n*sizeof(float));
 }
 
-void bias_output(const convolutional_layer layer)
+void bias_output(float *output, float *biases, int batch, int n, int size)
 {
     int i,j,b;
-    int out_h = convolutional_out_height(layer);
-    int out_w = convolutional_out_width(layer);
-    for(b = 0; b < layer.batch; ++b){
-        for(i = 0; i < layer.n; ++i){
-            for(j = 0; j < out_h*out_w; ++j){
-                layer.output[(b*layer.n + i)*out_h*out_w + j] = layer.biases[i];
+    for(b = 0; b < batch; ++b){
+        for(i = 0; i < n; ++i){
+            for(j = 0; j < size; ++j){
+                output[(b*n + i)*size + j] = biases[i];
             }
         }
     }
 }
 
+void backward_bias(float *bias_updates, float *delta, int batch, int n, int size)
+{
+    float alpha = 1./batch;
+    int i,b;
+    for(b = 0; b < batch; ++b){
+        for(i = 0; i < n; ++i){
+            bias_updates[i] += alpha * sum_array(delta+size*(i+b*n), size);
+        }
+    }
+}
+
+
 void forward_convolutional_layer(const convolutional_layer layer, float *in)
 {
     int out_h = convolutional_out_height(layer);
     int out_w = convolutional_out_width(layer);
     int i;
 
-    bias_output(layer);
+    bias_output(layer.output, layer.biases, layer.batch, layer.n, out_h*out_w);
 
     int m = layer.n;
     int k = layer.size*layer.size*layer.c;
@@ -151,19 +161,6 @@ void forward_convolutional_layer(const convolutional_layer layer, float *in)
     activate_array(layer.output, m*n*layer.batch, layer.activation);
 }
 
-void learn_bias_convolutional_layer(convolutional_layer layer)
-{
-    float alpha = 1./layer.batch;
-    int i,b;
-    int size = convolutional_out_height(layer)
-        *convolutional_out_width(layer);
-    for(b = 0; b < layer.batch; ++b){
-        for(i = 0; i < layer.n; ++i){
-            layer.bias_updates[i] += alpha * sum_array(layer.delta+size*(i+b*layer.n), size);
-        }
-    }
-}
-
 void backward_convolutional_layer(convolutional_layer layer, float *in, float *delta)
 {
     float alpha = 1./layer.batch;
@@ -174,8 +171,7 @@ void backward_convolutional_layer(convolutional_layer layer, float *in, float *d
         convolutional_out_width(layer);
 
     gradient_array(layer.output, m*k*layer.batch, layer.activation, layer.delta);
-
-    learn_bias_convolutional_layer(layer);
+    backward_bias(layer.bias_updates, layer.delta, layer.batch, layer.n, k);
 
     if(delta) memset(delta, 0, layer.batch*layer.h*layer.w*layer.c*sizeof(float));
 
diff --git a/src/convolutional_layer.h b/src/convolutional_layer.h
index c69686f3..dcc48bbd 100644
--- a/src/convolutional_layer.h
+++ b/src/convolutional_layer.h
@@ -45,10 +45,12 @@ typedef struct {
 void forward_convolutional_layer_gpu(convolutional_layer layer, float * in);
 void backward_convolutional_layer_gpu(convolutional_layer layer, float * in, float * delta_gpu);
 void update_convolutional_layer_gpu(convolutional_layer layer);
+
 void push_convolutional_layer(convolutional_layer layer);
 void pull_convolutional_layer(convolutional_layer layer);
-void learn_bias_convolutional_layer_ongpu(convolutional_layer layer);
-void bias_output_gpu(const convolutional_layer layer);
+
+void bias_output_gpu(float *output, float *biases, int batch, int n, int size);
+void backward_bias_gpu(float *bias_updates, float *delta, int batch, int n, int size);
 #endif
 
 convolutional_layer *make_convolutional_layer(int batch, int h, int w, int c, int n, int size, int stride, int pad, ACTIVATION activation, float learning_rate, float momentum, float decay);
@@ -59,14 +61,15 @@ image *visualize_convolutional_layer(convolutional_layer layer, char *window, im
 
 void backward_convolutional_layer(convolutional_layer layer, float *in, float *delta);
 
-void bias_output(const convolutional_layer layer);
+void bias_output(float *output, float *biases, int batch, int n, int size);
+void backward_bias(float *bias_updates, float *delta, int batch, int n, int size);
+
 image get_convolutional_image(convolutional_layer layer);
 image get_convolutional_delta(convolutional_layer layer);
 image get_convolutional_filter(convolutional_layer layer, int i);
 
 int convolutional_out_height(convolutional_layer layer);
 int convolutional_out_width(convolutional_layer layer);
-void learn_bias_convolutional_layer(convolutional_layer layer);
 
 #endif
 
diff --git a/src/darknet.c b/src/darknet.c
index 8bb5a74b..0b93aa68 100644
--- a/src/darknet.c
+++ b/src/darknet.c
@@ -225,8 +225,7 @@ char *basename(char *cfgfile)
 void train_imagenet(char *cfgfile, char *weightfile)
 {
     float avg_loss = -1;
-    // TODO
-    srand(0);
+    srand(time(0));
     char *base = basename(cfgfile);
     printf("%s\n", base);
     network net = parse_network_cfg(cfgfile);
@@ -585,25 +584,6 @@ void visualize_cat()
     cvWaitKey(0);
 }
 
-#ifdef GPU
-void test_convolutional_layer()
-{
-    network net = parse_network_cfg("cfg/nist_conv.cfg");
-    int size = get_network_input_size(net);
-    float *in = calloc(size, sizeof(float));
-    int i;
-    for(i = 0; i < size; ++i) in[i] = rand_normal();
-    convolutional_layer layer = *(convolutional_layer *)net.layers[0];
-    int out_size = convolutional_out_height(layer)*convolutional_out_width(layer)*layer.batch;
-    cuda_compare(layer.output_gpu, layer.output, out_size, "nothing");
-    cuda_compare(layer.biases_gpu, layer.biases, layer.n, "biases");
-    cuda_compare(layer.filters_gpu, layer.filters, layer.n*layer.size*layer.size*layer.c, "filters");
-    bias_output(layer);
-    bias_output_gpu(layer);
-    cuda_compare(layer.output_gpu, layer.output, out_size, "biased output");
-}
-#endif
-
 void test_correct_nist()
 {
     network net = parse_network_cfg("cfg/nist_conv.cfg");