diff --git a/base32.cpp b/base32.cpp
index 80ca4561..3c7e6ee9 100644
--- a/base32.cpp
+++ b/base32.cpp
@@ -18,7 +18,7 @@ void Base32Encoder::IsolatedInitialize(const NameValuePairs &parameters)
 
 void Base32Decoder::IsolatedInitialize(const NameValuePairs &parameters)
 {
-	BaseN_Decoder::Initialize(CombinedNameValuePairs(
+	BaseN_Decoder::IsolatedInitialize(CombinedNameValuePairs(
 		parameters,
 		MakeParameters(Name::DecodingLookupArray(), GetDefaultDecodingLookupArray(), false)(Name::Log2Base(), 5, true)));
 }
diff --git a/base64.cpp b/base64.cpp
index 68c48e8e..0edce9ea 100644
--- a/base64.cpp
+++ b/base64.cpp
@@ -47,6 +47,13 @@ void Base64URLEncoder::IsolatedInitialize(const NameValuePairs &parameters)
 			(Name::Log2Base(), 6, true)));
 }
 
+void Base64Decoder::IsolatedInitialize(const NameValuePairs &parameters)
+{
+	BaseN_Decoder::IsolatedInitialize(CombinedNameValuePairs(
+		parameters,
+		MakeParameters(Name::DecodingLookupArray(), GetDecodingLookupArray(), false)(Name::Log2Base(), 6, true)));
+}
+
 const int *Base64Decoder::GetDecodingLookupArray()
 {
 	static volatile bool s_initialized = false;
@@ -60,6 +67,13 @@ const int *Base64Decoder::GetDecodingLookupArray()
 	return s_array;
 }
 
+void Base64URLDecoder::IsolatedInitialize(const NameValuePairs &parameters)
+{
+	BaseN_Decoder::IsolatedInitialize(CombinedNameValuePairs(
+		parameters,
+		MakeParameters(Name::DecodingLookupArray(), GetDecodingLookupArray(), false)(Name::Log2Base(), 6, true)));
+}
+
 const int *Base64URLDecoder::GetDecodingLookupArray()
 {
 	static volatile bool s_initialized = false;
diff --git a/base64.h b/base64.h
index 0a6d7768..1f2e44db 100644
--- a/base64.h
+++ b/base64.h
@@ -62,8 +62,7 @@ public:
 	//! \details IsolatedInitialize() is used to initialize or reinitialize an object using a variable
 	//!   number of arbitrarily typed arguments. IsolatedInitialize() does not call Initialize() on
 	//!  attached transformations. If initialization should be propagated, then use the Initialize() function.
-	void IsolatedInitialize(const NameValuePairs &parameters)
-		{CRYPTOPP_UNUSED(parameters);}
+	void IsolatedInitialize(const NameValuePairs &parameters);
     
 private:
 	static const int * CRYPTOPP_API GetDecodingLookupArray();
@@ -123,8 +122,7 @@ public:
 	//! \details IsolatedInitialize() is used to initialize or reinitialize an object using a variable
 	//!   number of arbitrarily typed arguments. IsolatedInitialize() does not call Initialize() on
 	//!  attached transformations. If initialization should be propagated, then use the Initialize() function.
-	void IsolatedInitialize(const NameValuePairs &parameters)
-		{CRYPTOPP_UNUSED(parameters);}
+	void IsolatedInitialize(const NameValuePairs &parameters);
     
 private:
 	static const int * CRYPTOPP_API GetDecodingLookupArray();