diff --git a/src/blockfilter.h b/src/blockfilter.h
--- a/src/blockfilter.h
+++ b/src/blockfilter.h
@@ -81,8 +81,9 @@
 constexpr uint8_t BASIC_FILTER_P = 19;
 constexpr uint32_t BASIC_FILTER_M = 784931;
 
-enum BlockFilterType : uint8_t {
+enum class BlockFilterType : uint8_t {
     BASIC = 0,
+    INVALID = 255,
 };
 
 /**
@@ -91,7 +92,7 @@
  */
 class BlockFilter {
 private:
-    BlockFilterType m_filter_type;
+    BlockFilterType m_filter_type = BlockFilterType::INVALID;
     uint256 m_block_hash;
     GCSFilter m_filter;
 
diff --git a/src/blockfilter.cpp b/src/blockfilter.cpp
--- a/src/blockfilter.cpp
+++ b/src/blockfilter.cpp
@@ -249,6 +249,8 @@
             params.m_P = BASIC_FILTER_P;
             params.m_M = BASIC_FILTER_M;
             return true;
+        case BlockFilterType::INVALID:
+            return false;
     }
 
     return false;
diff --git a/src/test/blockfilter_tests.cpp b/src/test/blockfilter_tests.cpp
--- a/src/test/blockfilter_tests.cpp
+++ b/src/test/blockfilter_tests.cpp
@@ -116,11 +116,19 @@
     stream << block_filter;
     stream >> block_filter2;
 
-    BOOST_CHECK_EQUAL(block_filter.GetFilterType(),
-                      block_filter2.GetFilterType());
+    BOOST_CHECK(block_filter.GetFilterType() == block_filter2.GetFilterType());
     BOOST_CHECK(block_filter.GetBlockHash() == block_filter2.GetBlockHash());
     BOOST_CHECK(block_filter.GetEncodedFilter() ==
                 block_filter2.GetEncodedFilter());
+
+    BlockFilter default_ctor_block_filter_1;
+    BlockFilter default_ctor_block_filter_2;
+    BOOST_CHECK(default_ctor_block_filter_1.GetFilterType() ==
+                default_ctor_block_filter_2.GetFilterType());
+    BOOST_CHECK(default_ctor_block_filter_1.GetBlockHash() ==
+                default_ctor_block_filter_2.GetBlockHash());
+    BOOST_CHECK(default_ctor_block_filter_1.GetEncodedFilter() ==
+                default_ctor_block_filter_2.GetEncodedFilter());
 }
 
 BOOST_AUTO_TEST_CASE(blockfilters_json_test) {