diff --git a/src/utils.cc b/src/utils.cc
index b2666d3..23d8479 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -185,7 +185,7 @@
   // 0      1     0x1F
   // 1      1     0x8B
   // 2      1     compression method (8 denotes deflate)
-  static const uint8_t magic[] = {0x1F, 0x8B, 8};
+  static constexpr uint8_t magic[] = {0x1F, 0x8B, 8};
   return size >= 10 && std::equal(std::begin(magic), std::end(magic), header);
 }
 }  // namespace
@@ -240,10 +240,10 @@
     offset += compressed_size;
 
     // Ignore CRC32 and uncompressed size.
-    TEST_AND_RETURN_FALSE(offset + 8 <= data.size());
     offset += 8;
     member_start = offset;
-  } while (IsValidGzipHeader(&data[member_start], data.size() - member_start));
+  } while (member_start < data.size() &&
+           IsValidGzipHeader(&data[member_start], data.size() - member_start));
   return true;
 }