diff --git a/libretro-common/formats/png/rpng.c b/libretro-common/formats/png/rpng.c
index 1c2b2de1d9..8831cab5a4 100644
--- a/libretro-common/formats/png/rpng.c
+++ b/libretro-common/formats/png/rpng.c
@@ -959,11 +959,6 @@ static bool read_chunk_header(uint8_t *buf, uint8_t *buf_end,
 
    dword[0] = '\0';
 
-   /* Check whether reading the header will overflow
-    * the data buffer */
-   if (buf_end - buf < 8)
-      return false;
-
    for (i = 0; i < 4; i++)
       dword[i] = buf[i];
 
@@ -1019,6 +1014,10 @@ bool rpng_iterate_image(rpng_t *rpng)
    if (buf > rpng->buff_end)
       return false;
 
+   /* Check whether reading the header will overflow
+    * the data buffer */
+   if (rpng->buff_end - buf < 8)
+      return false;
    if (!read_chunk_header(buf, rpng->buff_end, &chunk))
       return false;