diff --git a/include/exiv2/exif.hpp b/include/exiv2/exif.hpp
index 31322730..71a73de3 100644
--- a/include/exiv2/exif.hpp
+++ b/include/exiv2/exif.hpp
@@ -35,7 +35,6 @@
 #include "tags.hpp"
 #include "value.hpp"
 #include "types.hpp"
-#include "tags_int.hpp"
 
 // + standard includes
 #include <string>
@@ -249,47 +248,7 @@ namespace Exiv2 {
 
 			@return true if it can be ignored, false otherwise.
 		*/
-		bool ignore(void) const
-		{
-			bool bRet = false;
-
-			const Value &v = value();
-			if (v.count() > 0)
-			{
-				const TagInfo* ti = Internal::tagInfo(tag(), static_cast<Internal::IfdId>(ifdId()));
-				if (ti && ti->hasUndefined_)
-				{
-					const Value &udv = ti->undefValue_;
-					if ((udv.count() != 0))
-					{
-						switch (ti->compT_)
-						{
-							case TagInfo::String:
-							{
-								bRet = compare<std::string>(v.toString(), udv.toString(), ti->compO_);
-								break;
-							}
-							case TagInfo::Long:
-							{
-								bRet = compare<long>(v.toLong(), udv.toLong(), ti->compO_);
-								break;
-							}
-							case TagInfo::Float:
-							{
-								bRet = compare<float>(v.toFloat(), udv.toFloat(), ti->compO_);
-								break;
-							}
-							case TagInfo::Rational:
-							{
-								bRet = compare<Rational>(v.toRational(), udv.toRational(), ti->compO_);
-								break;
-							}
-						}
-					}
-				}
-			}
-			return bRet;
-		}
+		bool ignore(void) const;
         //! Return the size of the data area.
         long sizeDataArea() const;
         /*!
diff --git a/src/exif.cpp b/src/exif.cpp
index d7f5ad04..9c1c2cf7 100644
--- a/src/exif.cpp
+++ b/src/exif.cpp
@@ -417,7 +417,49 @@ namespace Exiv2 {
         return value_.get() == 0 ? Value::AutoPtr(0) : value_->clone();
     }
 
-    long Exifdatum::sizeDataArea() const
+	bool Exifdatum::ignore(void) const
+	{
+		bool bRet = false;
+
+		const Value &v = value();
+		if (v.count() > 0)
+		{
+			const TagInfo* ti = Internal::tagInfo(tag(), static_cast<Internal::IfdId>(ifdId()));
+			if (ti && ti->hasUndefined_)
+			{
+				const Value &udv = ti->undefValue_;
+				if ((udv.count() != 0))
+				{
+					switch (ti->compT_)
+					{
+					case TagInfo::String:
+					{
+						bRet = compare<std::string>(v.toString(), udv.toString(), ti->compO_);
+						break;
+					}
+					case TagInfo::Long:
+					{
+						bRet = compare<long>(v.toLong(), udv.toLong(), ti->compO_);
+						break;
+					}
+					case TagInfo::Float:
+					{
+						bRet = compare<float>(v.toFloat(), udv.toFloat(), ti->compO_);
+						break;
+					}
+					case TagInfo::Rational:
+					{
+						bRet = compare<Rational>(v.toRational(), udv.toRational(), ti->compO_);
+						break;
+					}
+					}
+				}
+			}
+		}
+		return bRet;
+	}
+
+	long Exifdatum::sizeDataArea() const
     {
         return value_.get() == 0 ? 0 : value_->sizeDataArea();
     }