diff --git a/libuavcan/include/uavcan/data_type.hpp b/libuavcan/include/uavcan/data_type.hpp
index 642845136c..bfb2f58e79 100644
--- a/libuavcan/include/uavcan/data_type.hpp
+++ b/libuavcan/include/uavcan/data_type.hpp
@@ -67,33 +67,13 @@ class UAVCAN_EXPORT DataTypeSignatureCRC
     uint64_t crc_;
 
 public:
-    static DataTypeSignatureCRC extend(uint64_t crc)
-    {
-        DataTypeSignatureCRC ret;
-        ret.crc_ = crc ^ 0xFFFFFFFFFFFFFFFF;
-        return ret;
-    }
+    static DataTypeSignatureCRC extend(uint64_t crc);
 
     DataTypeSignatureCRC() : crc_(0xFFFFFFFFFFFFFFFF) { }
 
-    void add(uint8_t byte)
-    {
-        static const uint64_t Poly = 0x42F0E1EBA9EA3693;
-        crc_ ^= uint64_t(byte) << 56;
-        for (int i = 0; i < 8; i++)
-        {
-            crc_ = (crc_ & (uint64_t(1) << 63)) ? (crc_ << 1) ^ Poly : crc_ << 1;
-        }
-    }
+    void add(uint8_t byte);
 
-    void add(const uint8_t* bytes, unsigned len)
-    {
-        assert(bytes);
-        while (len--)
-        {
-            add(*bytes++);
-        }
-    }
+    void add(const uint8_t* bytes, unsigned len);
 
     uint64_t get() const { return crc_ ^ 0xFFFFFFFFFFFFFFFF; }
 };
diff --git a/libuavcan/src/uc_data_type.cpp b/libuavcan/src/uc_data_type.cpp
index d5418c528a..6c71cb9bcf 100644
--- a/libuavcan/src/uc_data_type.cpp
+++ b/libuavcan/src/uc_data_type.cpp
@@ -9,6 +9,35 @@
 
 namespace uavcan
 {
+/*
+ * DataTypeSignatureCRC
+ */
+DataTypeSignatureCRC DataTypeSignatureCRC::extend(uint64_t crc)
+{
+    DataTypeSignatureCRC ret;
+    ret.crc_ = crc ^ 0xFFFFFFFFFFFFFFFF;
+    return ret;
+}
+
+void DataTypeSignatureCRC::add(uint8_t byte)
+{
+    static const uint64_t Poly = 0x42F0E1EBA9EA3693;
+    crc_ ^= uint64_t(byte) << 56;
+    for (int i = 0; i < 8; i++)
+    {
+        crc_ = (crc_ & (uint64_t(1) << 63)) ? (crc_ << 1) ^ Poly : crc_ << 1;
+    }
+}
+
+void DataTypeSignatureCRC::add(const uint8_t* bytes, unsigned len)
+{
+    assert(bytes);
+    while (len--)
+    {
+        add(*bytes++);
+    }
+}
+
 /*
  * DataTypeSignature
  */