diff --git a/src/samplers/magick.c b/src/samplers/magick.c
index f0bc10a..379b7a5 100644
--- a/src/samplers/magick.c
+++ b/src/samplers/magick.c
@@ -13,6 +13,9 @@ simdb_record_create(simdb_rec_t * const rec, const char * const source) {
   size_t buf_size = 64 * sizeof(char);
   unsigned char *buf = NULL;
 
+  assert(rec != NULL);
+  assert(source != NULL);
+
   InitializeMagick("/");
   wand = NewMagickWand();
   if (status == MagickPass)