diff --git a/DigestPlay.c b/DigestPlay.c
index f869d2d..568ce01 100644
--- a/DigestPlay.c
+++ b/DigestPlay.c
@@ -139,10 +139,9 @@ int main(int argc, char* argv[])
   // Check input data format
 
   char* buffer = (char*)alloca(BUFFER_SIZE);
-  ssize_t length = read(STDIN_FILENO, buffer, DSD_MAGIC_SIZE);
 
-  if ((length != DSD_MAGIC_SIZE) ||
-      (memcmp(buffer, DSD_MAGIC_TEXT, length) != 0))
+  if ((read(STDIN_FILENO, buffer, DSD_MAGIC_SIZE) != DSD_MAGIC_SIZE) ||
+      (memcmp(buffer, DSD_MAGIC_TEXT, DSD_MAGIC_SIZE) != 0))
   {
     printf("Error checking input data format\n");
     ReleaseRewindContext(context);