diff --git a/cpp/devices/tape.cpp b/cpp/devices/tape.cpp
index 022fc859..6fcba8f6 100644
--- a/cpp/devices/tape.cpp
+++ b/cpp/devices/tape.cpp
@@ -327,7 +327,7 @@ void Tape::AddModeBlockDescriptor(map<int, vector<byte>> &pages) const
 
 void Tape::AddDataCompressionPage(map<int, vector<byte>> &pages) const
 {
-    vector<byte> buf(14);
+    vector<byte> buf(16);
 
     pages[15] = buf;
 }
diff --git a/cpp/test/tape_test.cpp b/cpp/test/tape_test.cpp
index 186c5748..f8cce892 100644
--- a/cpp/test/tape_test.cpp
+++ b/cpp/test/tape_test.cpp
@@ -24,7 +24,7 @@ static void ValidateModePages(map<int, vector<byte>> &pages)
     EXPECT_EQ(12U, pages[1].size());
     EXPECT_EQ(16U, pages[2].size());
     EXPECT_EQ(8U, pages[10].size());
-    EXPECT_EQ(14U, pages[15].size());
+    EXPECT_EQ(16U, pages[15].size());
     EXPECT_EQ(16U, pages[16].size());
     EXPECT_EQ(10U, pages[17].size());
 }