diff --git a/ex-6/main.c b/ex-6/main.c
index d3b9831..77e3dd7 100644
--- a/ex-6/main.c
+++ b/ex-6/main.c
@@ -115,6 +115,26 @@ gsl_histogram* histogram_convolve(gsl_histogram *a, gsl_histogram *b) {
 }
 
 
+int show_help(char **argv) {
+  fprintf(stderr, "Usage: %s -[hcdoebsrmn]\n", argv[0]);
+  fprintf(stderr, "  -h\t\tShow this message.\n");
+  fprintf(stderr, "  -c\t\tPrint the convolved histogram to stdout.\n");
+  fprintf(stderr, "  -d\t\tAttempt and print the deconvolved histogram.\n");
+  fprintf(stderr, "  -o\t\tPrint the original histogram to stdout.\n");
+  fprintf(stderr, "  -e N\t\tThe number of events. (default: 50000)\n");
+  fprintf(stderr, "  -b N\t\tThe number of θ bins. (default: 150)\n");
+  fprintf(stderr, "  -s SIGMA\tThe sigma of gaussian kernel. "
+                  "(default: 0.8)\n");
+  fprintf(stderr, "  -r N\t\tThe number of RL deconvolution rounds."
+                  "(default: 3)\n");
+  fprintf(stderr, "  -m MODE\tThe deconvolution mode: 'fft' or 'rl'."
+                  "(default: 'fft')\n");
+  fprintf(stderr, "  -n SIGMA\tThe σ of the gaussian noise to add to "
+                  "the convolution. (default: 0)\n");
+  return EXIT_SUCCESS;
+}
+
+
 int main(int argc, char **argv) {
   struct options opts;
   /* Set default options */
@@ -139,20 +159,7 @@ int main(int argc, char **argv) {
     else if (!strcmp(argv[i], "-r")) opts.rounds      = atol(argv[++i]);
     else if (!strcmp(argv[i], "-m")) opts.mode        = argv[++i];
     else if (!strcmp(argv[i], "-n")) opts.noise       = atof(argv[++i]);
-    else {
-      fprintf(stderr, "Usage: %s -[cdoebsrmh]\n", argv[0]);
-      fprintf(stderr, "\t-h\t\tShow this message.\n");
-      fprintf(stderr, "\t-c\t\tPrint the convolved histogram to stdout.\n");
-      fprintf(stderr, "\t-d\t\tAttempt and print the deconvolved histogram.\n");
-      fprintf(stderr, "\t-o\t\tPrint the original histogram to stdout.\n");
-      fprintf(stderr, "\t-e N\t\tThe number of events. (default: 50000)\n");
-      fprintf(stderr, "\t-b N\t\tThe number of θ bins. (default: 150)\n");
-      fprintf(stderr, "\t-s SIGMA\tThe sigma of gaussian kernel.(default: 0.8)\n");
-      fprintf(stderr, "\t-r N\t\tThe number of RL deconvolution rounds. (default: 3)\n");
-      fprintf(stderr, "\t-m MODE\t\tThe deconvolution mode: 'fft' or 'rl'. (default: 'fft')\n");
-      fprintf(stderr, "\t-n MU\t\tThe mean (μ) of Poisson noise to add to the convolution. (default: 0)\n");
-      return EXIT_FAILURE;
-    }
+    else return show_help(argv);
   }
 
   /* Initialize an RNG. */
@@ -192,13 +199,13 @@ int main(int argc, char **argv) {
   gsl_histogram *conv = histogram_convolve(hist, kernel);
   fputs("done\n", stderr);
 
-  /* Add Poisson noise with μ=opts.noise to
+  /* Add gaussian noise with σ=opts.noise to
    * the convolution.
    */
   if (opts.noise > 0) {
-    fputs("2.1 adding poisson noise...", stderr);
+    fputs("2.1 adding noise...", stderr);
     for (size_t i = 0; i < conv->n; i++)
-      conv->bin[i] += gsl_ran_poisson(r, opts.noise);
+      conv->bin[i] += conv->bin[i] * gsl_ran_gaussian(r, opts.noise);
     fputs("done\n", stderr);
   }