diff --git a/src/common/cstr.h b/src/common/cstr.h
index 89a84206..6d481974 100644
--- a/src/common/cstr.h
+++ b/src/common/cstr.h
@@ -51,6 +51,7 @@ DEF_CSTR(fileu, "file://");
 DEF_CSTR(fmtime, "fmtime");
 DEF_CSTR(ipath, "ipath");
 DEF_CSTR(iso_8859_1, "ISO-8859-1");
+DEF_CSTR(md5, "md5");
 DEF_CSTR(mimetype, "mimetype");
 DEF_CSTR(minwilds, "*?[");
 DEF_CSTR(newline, "\n");
diff --git a/src/internfile/mh_exec.cpp b/src/internfile/mh_exec.cpp
index 536c583f..40a8caf4 100644
--- a/src/internfile/mh_exec.cpp
+++ b/src/internfile/mh_exec.cpp
@@ -165,7 +165,7 @@ void MimeHandlerExec::finaldetails()
 
     string md5, xmd5, reason;
     if (MD5File(m_fn, md5, &reason)) {
-	m_metaData["md5"] = MD5HexPrint(md5, xmd5);
+	m_metaData[cstr_md5] = MD5HexPrint(md5, xmd5);
     } else {
 	LOGERR(("MimeHandlerExec: cant compute md5 for [%s]: %s\n", 
 		m_fn.c_str(), reason.c_str()));
diff --git a/src/internfile/mh_execm.cpp b/src/internfile/mh_execm.cpp
index 1c77ce1b..c40d5494 100644
--- a/src/internfile/mh_execm.cpp
+++ b/src/internfile/mh_execm.cpp
@@ -268,13 +268,13 @@ bool MimeHandlerExecMultiple::next_document()
         m_metaData[cstr_mimetype] = mtype;
         string md5, xmd5;
         MD5String(m_metaData[cstr_content], md5);
-        m_metaData["md5"] = MD5HexPrint(md5, xmd5);
+        m_metaData[cstr_md5] = MD5HexPrint(md5, xmd5);
     } else {
         m_metaData[cstr_mimetype] = mtype.empty() ? "text/html" : mtype;
         m_metaData.erase(cstr_ipath);
         string md5, xmd5, reason;
         if (MD5File(m_fn, md5, &reason)) {
-            m_metaData["md5"] = MD5HexPrint(md5, xmd5);
+            m_metaData[cstr_md5] = MD5HexPrint(md5, xmd5);
         } else {
             LOGERR(("MimeHandlerExecM: cant compute md5 for [%s]: %s\n",
                     m_fn.c_str(), reason.c_str()));
diff --git a/src/internfile/mh_html.cpp b/src/internfile/mh_html.cpp
index 80277cf1..237caf8a 100644
--- a/src/internfile/mh_html.cpp
+++ b/src/internfile/mh_html.cpp
@@ -56,7 +56,7 @@ bool MimeHandlerHtml::set_document_string(const string& htext)
     // We want to compute the md5 now because we may modify m_html later
     string md5, xmd5;
     MD5String(htext, md5);
-    m_metaData["md5"] = MD5HexPrint(md5, xmd5);
+    m_metaData[cstr_md5] = MD5HexPrint(md5, xmd5);
 
     return true;
 }
diff --git a/src/internfile/mh_mail.cpp b/src/internfile/mh_mail.cpp
index 6520e768..814f3bcf 100644
--- a/src/internfile/mh_mail.cpp
+++ b/src/internfile/mh_mail.cpp
@@ -100,7 +100,7 @@ bool MimeHandlerMail::set_document_file(const string &fn)
     // the md5 computation to the mime analysis, but ...
     string md5, xmd5, reason;
     if (MD5File(fn, md5, &reason)) {
-	m_metaData["md5"] = MD5HexPrint(md5, xmd5);
+	m_metaData[cstr_md5] = MD5HexPrint(md5, xmd5);
     } else {
 	LOGERR(("MimeHandlerMail: cant compute md5 for [%s]: %s\n", fn.c_str(),
 		reason.c_str()));
@@ -132,7 +132,7 @@ bool MimeHandlerMail::set_document_string(const string &msgtxt)
 
     string md5, xmd5;
     MD5String(msgtxt, md5);
-    m_metaData["md5"] = MD5HexPrint(md5, xmd5);
+    m_metaData[cstr_md5] = MD5HexPrint(md5, xmd5);
 
     m_stream = new stringstream(msgtxt);
     delete m_bincdoc;
diff --git a/src/internfile/mh_text.cpp b/src/internfile/mh_text.cpp
index ed3f260f..0d6ddf5f 100644
--- a/src/internfile/mh_text.cpp
+++ b/src/internfile/mh_text.cpp
@@ -81,7 +81,7 @@ bool MimeHandlerText::set_document_file(const string &fn)
 
     string md5, xmd5;
     MD5String(m_text, md5);
-    m_metaData["md5"] = MD5HexPrint(md5, xmd5);
+    m_metaData[cstr_md5] = MD5HexPrint(md5, xmd5);
     m_havedoc = true;
     return true;
 }
@@ -91,7 +91,7 @@ bool MimeHandlerText::set_document_string(const string& otext)
     m_text = otext;
     string md5, xmd5;
     MD5String(m_text, md5);
-    m_metaData["md5"] = MD5HexPrint(md5, xmd5);
+    m_metaData[cstr_md5] = MD5HexPrint(md5, xmd5);
     m_havedoc = true;
     return true;
 }