diff --git a/libavcodec/rpza.c b/libavcodec/rpza.c
index 0efd7f4712..83dde7a9c3 100644
--- a/libavcodec/rpza.c
+++ b/libavcodec/rpza.c
@@ -119,6 +119,8 @@ static void rpza_decode_stream(RpzaContext *s)
             }
         }
 
+        n_blocks = FFMIN(n_blocks, total_blocks);
+
         switch (opcode & 0xe0) {
 
         /* Skip blocks */