diff --git a/vp8/decoder/decodeframe.c b/vp8/decoder/decodeframe.c
index 4bc87eb13..566972ea7 100644
--- a/vp8/decoder/decodeframe.c
+++ b/vp8/decoder/decodeframe.c
@@ -986,7 +986,8 @@ int vp8_decode_frame(VP8D_COMP *pbi)
     VP8_COMMON *const pc = &pbi->common;
     MACROBLOCKD *const xd  = &pbi->mb;
     const unsigned char *data = pbi->fragments.ptrs[0];
-    const unsigned char *data_end =  data + pbi->fragments.sizes[0];
+    const unsigned int data_sz = pbi->fragments.sizes[0];
+    const unsigned char *data_end = data + data_sz;
     ptrdiff_t first_partition_length_in_bytes;
 
     int i, j, k, l;
@@ -1022,7 +1023,7 @@ int vp8_decode_frame(VP8D_COMP *pbi)
         const unsigned char *clear = data;
         if (pbi->decrypt_cb)
         {
-            int n = (int)VPXMIN(sizeof(clear_buffer), data_end - data);
+            int n = (int)VPXMIN(sizeof(clear_buffer), data_sz);
             pbi->decrypt_cb(pbi->decrypt_state, data, clear_buffer, n);
             clear = clear_buffer;
         }