diff --git a/DESCRIPTION b/DESCRIPTION
index f27979e..21e138e 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -18,6 +18,7 @@ Imports:
     formula.tools,
     GenomeInfoDb,
     GenomicAlignments,
+    GenomicFeatures,
     GenomicRanges (>= 1.37.16),
     ggplot2 (>= 2.2.0),
     gtools,
diff --git a/NAMESPACE b/NAMESPACE
index 0788b49..d835e37 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -105,6 +105,10 @@ importFrom(GenomeInfoDb,seqnames)
 importFrom(GenomeInfoDb,sortSeqlevels)
 importFrom(GenomicAlignments,qwidth)
 importFrom(GenomicAlignments,readGAlignments)
+importFrom(GenomicFeatures,exons)
+importFrom(GenomicFeatures,genes)
+importFrom(GenomicFeatures,promoters)
+importFrom(GenomicFeatures,transcripts)
 importFrom(GenomicRanges,GPos)
 importFrom(GenomicRanges,GRanges)
 importFrom(GenomicRanges,GRangesList)
diff --git a/man/annotateCTSS.Rd b/man/annotateCTSS.Rd
index 3573950..8d488d5 100644
--- a/man/annotateCTSS.Rd
+++ b/man/annotateCTSS.Rd
@@ -3,6 +3,7 @@
 \name{annotateCTSS}
 \alias{annotateCTSS}
 \alias{annotateCTSS,CAGEexp,GRanges-method}
+\alias{annotateCTSS,CAGEexp,TxDb-method}
 \alias{annotateTagClusters}
 \alias{annotateTagClusters,CAGEexp,GRanges-method}
 \alias{annotateConsensusClusters}
@@ -13,6 +14,8 @@ annotateCTSS(object, ranges, upstream = 500, downstream = 500)
 
 \S4method{annotateCTSS}{CAGEexp,GRanges}(object, ranges, upstream = 500, downstream = 500)
 
+\S4method{annotateCTSS}{CAGEexp,TxDb}(object, ranges)
+
 annotateTagClusters(object, ranges, upstream = 500, downstream = 500)
 
 \S4method{annotateTagClusters}{CAGEexp,GRanges}(object, ranges, upstream = 500, downstream = 500)
diff --git a/man/ranges2annot.Rd b/man/ranges2annot.Rd
index 180c0ed..2c17910 100644
--- a/man/ranges2annot.Rd
+++ b/man/ranges2annot.Rd
@@ -2,9 +2,12 @@
 % Please edit documentation in R/Annotations.R
 \name{ranges2annot}
 \alias{ranges2annot}
+\alias{txdb2annot}
 \title{Hierarchical annotation of genomic regions.}
 \usage{
 ranges2annot(ranges, annot, upstream = 500, downstream = 500)
+
+txdb2annot(ranges, annot)
 }
 \arguments{
 \item{ranges}{A \code{\link[GenomicRanges:GRanges-class]{GenomicRanges::GRanges}} object, for example extracted from