diff --git a/server/modules/filter/dbfwfilter/rules.cc b/server/modules/filter/dbfwfilter/rules.cc
index 4fc1a424b..836668cf7 100644
--- a/server/modules/filter/dbfwfilter/rules.cc
+++ b/server/modules/filter/dbfwfilter/rules.cc
@@ -156,6 +156,7 @@ bool ColumnsRule::matches_query(DbfwSession* session, GWBUF* buffer, char** msg)
         for (size_t i = 0; !rval && i < n_infos; ++i)
         {
             std::string tok = infos[i].column;
+            std::transform(tok.begin(), tok.end(), tok.begin(), ::tolower);
             ValueList::const_iterator it = std::find(m_values.begin(), m_values.end(), tok);
 
             if (it != m_values.end())
@@ -192,6 +193,7 @@ bool FunctionRule::matches_query(DbfwSession* session, GWBUF* buffer, char** msg
             for (size_t i = 0; i < n_infos; ++i)
             {
                 std::string tok = infos[i].name;
+                std::transform(tok.begin(), tok.end(), tok.begin(), ::tolower);
                 ValueList::const_iterator it = std::find(m_values.begin(), m_values.end(), tok);
 
                 if (it != m_values.end())
@@ -223,6 +225,7 @@ bool FunctionUsageRule::matches_query(DbfwSession* session, GWBUF* buffer, char*
             for (size_t j = 0; j < infos[i].n_fields; j++)
             {
                 std::string tok = infos[i].fields[j].column;
+                std::transform(tok.begin(), tok.end(), tok.begin(), ::tolower);
                 ValueList::const_iterator it = std::find(m_values.begin(), m_values.end(), tok);
 
                 if (it != m_values.end())
@@ -249,9 +252,12 @@ bool ColumnFunctionRule::matches_query(DbfwSession* session, GWBUF* buffer, char
 
         for (size_t i = 0; i < n_infos; ++i)
         {
+            std::string func = infos[i].name;
+            std::transform(func.begin(), func.end(), func.begin(), ::tolower);
+
             ValueList::const_iterator func_it = std::find(m_values.begin(),
                                                           m_values.end(),
-                                                          infos[i].name);
+                                                          func);
 
             if (func_it != m_values.end())
             {
@@ -259,16 +265,18 @@ bool ColumnFunctionRule::matches_query(DbfwSession* session, GWBUF* buffer, char
 
                 for (size_t j = 0; j < infos[i].n_fields; j++)
                 {
+                    std::string col = infos[i].fields[j].column;
+                    std::transform(col.begin(), col.end(), col.begin(), ::tolower);
                     ValueList::const_iterator col_it = std::find(m_columns.begin(),
                                                                  m_columns.end(),
-                                                                 infos[i].fields[j].column);
+                                                                 col);
 
                     if (col_it != m_columns.end())
                     {
                         MXS_NOTICE("rule '%s': query uses function '%s' with forbidden column: %s",
-                                   name().c_str(), func_it->c_str(), col_it->c_str());
+                                   name().c_str(), col.c_str(), func.c_str());
                         *msg = create_error("Permission denied to column '%s' with function '%s'.",
-                                            col_it->c_str(), func_it->c_str());
+                                            col.c_str(), func.c_str());
                         return true;
                     }
                 }
diff --git a/server/modules/filter/dbfwfilter/rules.hh b/server/modules/filter/dbfwfilter/rules.hh
index f56a80867..24657aa41 100644
--- a/server/modules/filter/dbfwfilter/rules.hh
+++ b/server/modules/filter/dbfwfilter/rules.hh
@@ -14,6 +14,8 @@
 
 #include "dbfwfilter.hh"
 
+#include <algorithm>
+
 #include <maxscale/pcre2.hh>
 
 /**
@@ -103,6 +105,11 @@ public:
 
 };
 
+static void make_lower(std::string& value)
+{
+    std::transform(value.begin(), value.end(), value.begin(), ::tolower);
+}
+
 class ValueListRule: public Rule
 {
     ValueListRule(const ValueListRule&);
@@ -119,6 +126,7 @@ protected:
         Rule(name, type),
         m_values(values)
     {
+        std::for_each(m_values.begin(), m_values.end(), make_lower);
     }
 
     ValueList m_values;