diff --git a/include/libeosio/WIF.hpp b/include/libeosio/WIF.hpp
index 040c392..767da80 100644
--- a/include/libeosio/WIF.hpp
+++ b/include/libeosio/WIF.hpp
@@ -32,11 +32,11 @@ namespace libeosio {
 /**
  * Key prefixes. (strings that is not equal to these prefixes are treated as legacy format.)
  */
-const std::string WIF_PUB_LEG = "EOS";
-const std::string WIF_PUB_K1  = "PUB_K1_";
-const std::string WIF_PVT_LEG = "";
-const std::string WIF_PVT_K1  = "PVT_K1_";
-const std::string WIF_SIG_K1  = "SIG_K1_";
+extern const std::string WIF_PUB_LEG;
+extern const std::string WIF_PUB_K1;
+extern const std::string WIF_PVT_LEG;
+extern const std::string WIF_PVT_K1;
+extern const std::string WIF_SIG_K1;
 
 /**
  * Encode an EC private key to WIF String.
diff --git a/src/WIF.cpp b/src/WIF.cpp
index 44869f2..9d8712d 100644
--- a/src/WIF.cpp
+++ b/src/WIF.cpp
@@ -30,6 +30,12 @@
 
 namespace libeosio {
 
+const std::string WIF_PUB_LEG = "EOS";
+const std::string WIF_PUB_K1  = "PUB_K1_";
+const std::string WIF_PVT_LEG = "";
+const std::string WIF_PVT_K1  = "PVT_K1_";
+const std::string WIF_SIG_K1  = "SIG_K1_";
+
 std::string wif_priv_encode(const ec_privkey_t& priv, const std::string& prefix) {
 
 	checksum_t check;