diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0dd67268..3ec89c6b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,6 +24,12 @@ add_subdirectory(third_party/gflags EXCLUDE_FROM_ALL)
 add_subdirectory(third_party/cctz EXCLUDE_FROM_ALL)
 add_subdirectory(third_party/abseil-cpp EXCLUDE_FROM_ALL)
 
+include(CheckCXXCompilerFlag)
+CHECK_CXX_COMPILER_FLAG("-Wundefined-var-template" CXX_COMPILER_SUPPORTS_UNDEF_VAR)
+if(${CXX_COMPILER_SUPPORTS_UNDEF_VAR})
+    add_compile_options("-Wno-undefined-var-template")
+endif()
+
 option(YAML_CPP_BUILD_TESTS "" OFF)
 add_subdirectory(third_party/yaml-cpp EXCLUDE_FROM_ALL)
 target_include_directories(yaml-cpp PUBLIC
diff --git a/lib/include/prjxray/xilinx/architectures.h b/lib/include/prjxray/xilinx/architectures.h
index 11958531..1ea937ee 100644
--- a/lib/include/prjxray/xilinx/architectures.h
+++ b/lib/include/prjxray/xilinx/architectures.h
@@ -19,6 +19,7 @@ class Architecture {
        public:
 	using Container = absl::variant<Series7>;
 	virtual const std::string& name() const = 0;
+	virtual ~Architecture() {}
 };
 
 class Series7 : public Architecture {