diff --git a/examples/histogram.c b/examples/histogram.c
index d6b2893..d93c3db 100644
--- a/examples/histogram.c
+++ b/examples/histogram.c
@@ -10,7 +10,7 @@ int main(int argc, char *argv[])
 {
     char *srcname = NULL, *dstname = NULL;
     pipi_image_t *img, *newimg, *tmp;
-    pipi_histogram_t* histogram;
+    pipi_histogram_t* histogram = NULL;
     int ret = 0;
     if(argc < 2)
     {
@@ -37,12 +37,13 @@ int main(int argc, char *argv[])
     histogram = pipi_new_histogram();
     pipi_get_image_histogram(tmp, histogram, PIPI_COLOR_R|PIPI_COLOR_G|PIPI_COLOR_B);
 
-
     pipi_render_histogram(tmp, histogram, PIPI_COLOR_R|PIPI_COLOR_G|PIPI_COLOR_B);
 
+    pipi_free_histogram(histogram);
+
     pipi_save(tmp, dstname);
     pipi_free(newimg);
-
+    pipi_free(tmp);
     return ret;
 }