diff --git a/R/GENESISClasses.R b/R/GENESISClasses.R
index 002a736..45b0d41 100644
--- a/R/GENESISClasses.R
+++ b/R/GENESISClasses.R
@@ -1,7 +1,5 @@
 # Rainer Walke, MPIDR Rostock
 
-require(data.table)
-
 #' @importFrom methods new show validObject
 NULL
 #' @importFrom data.table :=
@@ -184,7 +182,7 @@ readRegDeath <- function(infile)
   header <- bb[1:h2]
   footer <- bb[f1:f2]
 
-  rdft <- fread(infile, skip=h2, nrows=(f1-h2-1))
+  rdft <- data.table::fread(infile, skip=h2, nrows=(f1-h2-1))
 
   setnames(rdft, c("V1","V2","V3","V4","V5","V6","V7","V8","V9","V10"),
            c("Year","Region_Code","Region_Name","Age_Name","Total1","Male","Female","D_Total","D_Male","D_Female"))
@@ -223,7 +221,7 @@ readRegExp <- function(infile)
   header <- bb[1:h2]
   footer <- bb[f1:f2]
 
-  rexpt <- fread(infile, skip=h2, nrows=(f1-h2-1))
+  rexpt <- data.table::fread(infile, skip=h2, nrows=(f1-h2-1))
 
   setnames(rexpt, c("V1","V2","V3","V4","V5","V6","V7","V8","V9","V10","V11","V12"),
            c("Region_Code","Region_Name","Age_Name","Total1","Male","Female","D_Total","D_Male","D_Female",
diff --git a/R/HMDClasses.R b/R/HMDClasses.R
index f9dd66c..148e276 100644
--- a/R/HMDClasses.R
+++ b/R/HMDClasses.R
@@ -1,7 +1,5 @@
 # Rainer Walke, MPIDR Rostock
 
-require(data.table)
-
 #' @importFrom methods new show validObject
 NULL
 #' @importFrom data.table :=
@@ -178,7 +176,7 @@ setValidity("EX1",
 readLT1x1 <- function(infile)
 {
   LT0 <- readLines(infile, n=2)
-  LT1 <- fread(infile)
+  LT1 <- data.table::fread(infile)
 
   B1 <- sapply(strsplit(LT0,"[,\t;:]"), trimws)
   country <- B1[[1]][1]
@@ -195,7 +193,7 @@ readLT1x1 <- function(infile)
 readEX1x1 <- function(infile)
 {
   EX0 <- readLines(infile, n=2)
-  EX1 <- fread(infile)
+  EX1 <- data.table::fread(infile)
 
   B1 <- sapply(strsplit(EX0,"[,\t;:]"), trimws)
   country <- B1[[1]][1]