diff --git a/libuavcan/CMakeLists.txt b/libuavcan/CMakeLists.txt
index 7d23d707b0..f36514b0dc 100644
--- a/libuavcan/CMakeLists.txt
+++ b/libuavcan/CMakeLists.txt
@@ -121,7 +121,7 @@ if (DEBUG_BUILD)
     if (COMPILER_IS_GCC_COMPATIBLE)
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Werror -pedantic -Wfloat-equal -Wconversion")
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wsign-conversion -Wcast-align -Wmissing-declarations -Wlogical-op")
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wtype-limits -Wno-error=array-bounds")
+        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wdouble-promotion -Wswitch-enum -Wtype-limits -Wno-error=array-bounds")
         set(cpp03_flags "-std=c++03 -Wno-variadic-macros -Wno-long-long")
         set(optim_flags "-O3 -DNDEBUG -g0")
     else ()
diff --git a/libuavcan/include/uavcan/data_type.hpp b/libuavcan/include/uavcan/data_type.hpp
index 168adbe921..cc64c29d6f 100644
--- a/libuavcan/include/uavcan/data_type.hpp
+++ b/libuavcan/include/uavcan/data_type.hpp
@@ -19,10 +19,11 @@ class UAVCAN_EXPORT TransferCRC;
 enum DataTypeKind
 {
     DataTypeKindService,
-    DataTypeKindMessage,
-    NumDataTypeKinds
+    DataTypeKindMessage
 };
 
+static const uint8_t NumDataTypeKinds = 2;
+
 
 static inline DataTypeKind getDataTypeKindForTransferType(const TransferType tt)
 {
diff --git a/libuavcan/include/uavcan/transport/transfer.hpp b/libuavcan/include/uavcan/transport/transfer.hpp
index 6300eb4b18..7e5d5b8821 100644
--- a/libuavcan/include/uavcan/transport/transfer.hpp
+++ b/libuavcan/include/uavcan/transport/transfer.hpp
@@ -19,10 +19,11 @@ enum TransferType
 {
     TransferTypeServiceResponse  = 0,
     TransferTypeServiceRequest   = 1,
-    TransferTypeMessageBroadcast = 2,
-    NumTransferTypes = 3
+    TransferTypeMessageBroadcast = 2
 };
 
+static const uint8_t NumTransferTypes = 3;
+
 
 class UAVCAN_EXPORT TransferPriority
 {