diff --git a/lib/grpffmat.gd b/lib/grpffmat.gd
index b3c626c3b1..cfac52c599 100644
--- a/lib/grpffmat.gd
+++ b/lib/grpffmat.gd
@@ -26,7 +26,8 @@
 ##  </ManSection>
 ##  <#/GAPDoc>
 ##
-DeclareSynonym( "IsFFEMatrixGroup", IsFFECollCollColl and IsMatrixGroup );
+DeclareCategory( "IsFFEMatrixGroup", IsMatrixGroup );
+InstallTrueMethod( IsFFEMatrixGroup, IsFFECollCollColl and IsMatrixGroup );
 
 
 #############################################################################
diff --git a/lib/grpmat.gd b/lib/grpmat.gd
index 5ef8db275d..eabc1765e5 100644
--- a/lib/grpmat.gd
+++ b/lib/grpmat.gd
@@ -26,7 +26,8 @@
 ##  </ManSection>
 ##  <#/GAPDoc>
 ##
-DeclareSynonym( "IsMatrixGroup", IsRingElementCollCollColl and IsGroup );
+DeclareCategory( "IsMatrixGroup", IsGroup );
+InstallTrueMethod( IsMatrixGroup, IsRingElementCollCollColl and IsGroup );
 
 #############################################################################
 ##
diff --git a/lib/matobj1.gd b/lib/matobj1.gd
index afc33a3d15..0532865648 100644
--- a/lib/matobj1.gd
+++ b/lib/matobj1.gd
@@ -263,6 +263,36 @@ DeclareCategory( "IsMatrixObj", IsMatrixOrMatrixObj );
 DeclareCategory( "IsRowListMatrix", IsMatrixObj );
 
 
+
+#############################################################################
+##
+# Two filters to speed up some methods:
+DeclareFilter( "IsIntVector" );  # TODO: replace this legacy filter from matobjplist.gi with something better
+DeclareFilter( "IsFFEVector" );
+
+DeclareCategory( "IsFFEVectorObj", IsVectorObj );
+DeclareCategory( "IsCyclotomicVectorObj", IsVectorObj );
+
+DeclareCategory( "IsFFEMatrixOrMatrixObj", IsMatrixOrMatrixObj );
+# DeclareSynonym( "IsFFEMatrix", IsFFEMatrixOrMatrixObj and IsMatrix );
+# DeclareSynonym( "IsFFEMatrixObj", IsFFEMatrixOrMatrixObj and IsMatrixObj );
+# or maybe
+# DeclareProperty( "IsFFEMatrix", IsMatrix );
+# DeclareProperty( "IsFFEMatrixObj", IsMatrixObj );
+
+DeclareCategory( "IsCyclotomicMatrixOrMatrixObj", IsMatrixOrMatrixObj );
+# DeclareSynonym( "IsCyclotomicMatrix", IsCyclotomicMatrixOrMatrixObj and IsMatrix );
+# DeclareSynonym( "IsCyclotomicMatrixObj", IsCyclotomicMatrixOrMatrixObj and IsMatrixObj );
+# or maybe have them be properties with methods so users are not confused ?!?
+# DeclareProperty( "IsCyclotomicMatrix", IsMatrix );
+# DeclareProperty( "IsCyclotomicMatrixObj", IsMatrixObj );
+
+
+InstallTrueMethod( IsFFEMatrixOrMatrixObj, IsFFECollColl and IsMatrix );
+InstallTrueMethod( IsCyclotomicMatrixOrMatrixObj, IsCyclotomicCollColl and IsMatrix );
+
+
+
 #############################################################################
 ##
 #A  BaseDomain( <vector> )
diff --git a/lib/matobjplist.gd b/lib/matobjplist.gd
index 5bcd6d38db..2c591f4829 100644
--- a/lib/matobjplist.gd
+++ b/lib/matobjplist.gd
@@ -122,7 +122,3 @@ BindGlobal( "ROWSPOS", 4 );
 #BindGlobal( "BDPOS", 1 );   # see above
 BindGlobal( "ELSPOS", 2 );
 
-# Two filters to speed up some methods:
-DeclareFilter( "IsIntVector" );
-DeclareFilter( "IsFFEVector" );
-