diff --git a/server/core/maxscale_pcre2.cc b/server/core/maxscale_pcre2.cc
index db6599b9e..40ed3813f 100644
--- a/server/core/maxscale_pcre2.cc
+++ b/server/core/maxscale_pcre2.cc
@@ -263,7 +263,7 @@ std::string pcre2_substitute(pcre2_code* re,
                                   (PCRE2_SPTR) replace.c_str(), replace.length(),
                                   (PCRE2_UCHAR*) &rval[0], &size_tmp)) == PCRE2_ERROR_NOMEMORY)
     {
-        rval.resize(rval.size() * 2);
+        rval.resize(rval.size() * 2 + 1);
         size_tmp = rval.size();
     }
 
diff --git a/server/modules/filter/binlogfilter/binlogfiltersession.cc b/server/modules/filter/binlogfilter/binlogfiltersession.cc
index ee7d2df50..33cac4618 100644
--- a/server/modules/filter/binlogfilter/binlogfiltersession.cc
+++ b/server/modules/filter/binlogfilter/binlogfiltersession.cc
@@ -855,7 +855,7 @@ void BinlogFilterSession::checkStatement(GWBUF** buffer, const REP_HEADER& hdr)
         auto new_db = mxs::pcre2_substitute(config.rewrite_src, db, config.rewrite_dest, &err);
         auto new_sql = mxs::pcre2_substitute(config.rewrite_src, sql, config.rewrite_dest, &err);
 
-        if (new_db.empty() || new_sql.empty())
+        if ((new_db.empty() && !db.empty()) || (new_sql.empty() && !sql.empty()))
         {
             MXS_ERROR("PCRE2 error on pattern '%s' with replacement '%s': %s",
                       config.rewrite_src_pattern.c_str(),