diff --git a/.travis.yml b/.travis.yml
index 4be52271..4a37d8ef 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,7 @@
 
 # Setting up R deps
 language: r
-r: 3.2
+r: 3.1
 r_packages: covr
 cache: packages
 
diff --git a/DESCRIPTION b/DESCRIPTION
index fbe4ac27..917405b5 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -25,7 +25,7 @@ Description: Functions to simplify the analysis of Antimicrobial Resistance (AMR
     on antibiograms according to Leclercq (2013)
     <doi:10.1111/j.1469-0691.2011.03703.x>.
 Depends:
-    R (>= 3.2.0)
+    R (>= 3.1.0)
 Imports:
     dplyr (>= 0.7.0),
     data.table (>= 1.10.0),
diff --git a/NAMESPACE b/NAMESPACE
index 3b36d900..0e0c60bf 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -57,6 +57,7 @@ exportMethods(print.tbl)
 exportMethods(print.tbl_df)
 exportMethods(summary.mic)
 exportMethods(summary.rsi)
+importFrom(data.table,data.table)
 importFrom(dplyr,"%>%")
 importFrom(dplyr,all_vars)
 importFrom(dplyr,any_vars)
diff --git a/NEWS.md b/NEWS.md
index 5ed07fc0..cf984b00 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -9,6 +9,7 @@
 - New print format for tibbles and data.tables
 
 #### Changed
+- Support for older R versions, only R 3.1.0 and later is needed
 - Renamed dataset `ablist` to `antibiotics`
 - Renamed dataset `bactlist` to `microorganisms`
 - Added more microorganisms to `bactlist`
diff --git a/R/freq.R b/R/freq.R
index fb6d6a47..bb592c0e 100644
--- a/R/freq.R
+++ b/R/freq.R
@@ -337,7 +337,7 @@ freq <- function(x,
                  '; ',
                  (Count.rest / length(x)) %>% percent(force_zero = TRUE),
                  ')'),
-          '. Use `nmax` to show more rows.\n\n', sep = '')
+          '. Use `nmax` to show more rows.\n', sep = '')
 
     } else {
       print(
diff --git a/R/misc.R b/R/misc.R
index d0588eb4..b28f32dc 100644
--- a/R/misc.R
+++ b/R/misc.R
@@ -111,3 +111,12 @@ size_humanreadable <- function(bytes, decimals = 1) {
   out <- paste(sprintf(paste0("%.", decimals, "f"), bytes / (1024 ^ factor)), size[factor + 1])
   out
 }
+
+# strrep is only available in R 3.3 and later
+# and we want to support R 3.2 too, so:
+strrep <- function(x, times) {
+  for (i in 1:length(x)) {
+    x[i] <- paste(rep(x[i], times[i]), collapse = "")
+  }
+  x
+}
diff --git a/R/print.R b/R/print.R
index 377cb9ac..6cdb68d9 100644
--- a/R/print.R
+++ b/R/print.R
@@ -28,6 +28,7 @@
 #' @rdname print
 #' @name print
 #' @importFrom dplyr %>% n_groups group_vars group_size filter pull select
+#' @importFrom data.table data.table
 #' @exportMethod print.tbl_df
 #' @export
 #' @examples