diff --git a/R/rBinomDS.R b/R/rBinomDS.R
index 22bcbbf3..9ec42361 100644
--- a/R/rBinomDS.R
+++ b/R/rBinomDS.R
@@ -24,6 +24,7 @@
 #' also returns a vector reporting the length of the pseudorandom vector
 #' created in each source.
 #' @author Paul Burton for DataSHIELD Development Team
+#' @author Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 #' @export
 rBinomDS<-function (n, size = 1, prob = 0.5){
 
@@ -34,13 +35,11 @@ rBinomDS<-function (n, size = 1, prob = 0.5){
 #first convert their names into the corresponding active vectors
 
 	if(is.character(size)){
-	command.text<-size
-	size<-eval(parse(text=command.text), envir = parent.frame())
+	size<-.loadServersideObject(size)
 	}
 
 	if(is.character(prob)){
-	command.text<-prob
-	prob<-eval(parse(text=command.text), envir = parent.frame())
+	prob<-.loadServersideObject(prob)
 	}
 
 	stats::rbinom(n, size=size, prob=prob)
diff --git a/R/rNormDS.R b/R/rNormDS.R
index f50a424e..d201143a 100644
--- a/R/rNormDS.R
+++ b/R/rNormDS.R
@@ -29,6 +29,7 @@
 #' also returns a vector reporting the length of the pseudorandom vector
 #' created in each source.
 #' @author Paul Burton for DataSHIELD Development Team
+#' @author Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 #' @export
 rNormDS<-function (n, mean = 0, sd = 1, force.output.to.k.decimal.places=9){
 
@@ -39,13 +40,11 @@ rNormDS<-function (n, mean = 0, sd = 1, force.output.to.k.decimal.places=9){
 #first convert their names into the corresponding active vectors
 
 	if(is.character(mean)){
-	command.text<-mean
-	mean<-eval(parse(text=command.text), envir = parent.frame())
+	mean<-.loadServersideObject(mean)
 	}
 
 	if(is.character(sd)){
-	command.text<-sd
-	sd<-eval(parse(text=command.text), envir = parent.frame())
+	sd<-.loadServersideObject(sd)
 	}
 
 	random.number.vector<-stats::rnorm(n, mean=mean, sd=sd)
diff --git a/R/rPoisDS.R b/R/rPoisDS.R
index 3274078c..5bee2148 100644
--- a/R/rPoisDS.R
+++ b/R/rPoisDS.R
@@ -20,6 +20,7 @@
 #' also returns a vector reporting the length of the pseudorandom vector
 #' created in each source.
 #' @author Paul Burton for DataSHIELD Development Team
+#' @author Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 #' @export
 rPoisDS<-function (n, lambda = 1){
 
@@ -30,8 +31,7 @@ rPoisDS<-function (n, lambda = 1){
 #first convert its name into the corresponding active vectors
 
 	if(is.character(lambda)){
-	command.text<-lambda
-	lambda<-eval(parse(text=command.text), envir = parent.frame())
+	lambda<-.loadServersideObject(lambda)
 	}
 
 	stats::rpois(n, lambda=lambda)
diff --git a/R/rUnifDS.R b/R/rUnifDS.R
index 9f4463c6..d20d189f 100644
--- a/R/rUnifDS.R
+++ b/R/rUnifDS.R
@@ -29,6 +29,7 @@
 #' also returns a vector reporting the length of the pseudorandom vector
 #' created in each source.
 #' @author Paul Burton for DataSHIELD Development Team
+#' @author Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 #' @export
 rUnifDS<-function (n, min = 0, max = 1, force.output.to.k.decimal.places=9){
 
@@ -39,13 +40,11 @@ rUnifDS<-function (n, min = 0, max = 1, force.output.to.k.decimal.places=9){
 #first convert their names into the corresponding active vectors
 
 	if(is.character(min)){
-	command.text<-min
-	min<-eval(parse(text=command.text), envir = parent.frame())
+	min<-.loadServersideObject(min)
 	}
 
 	if(is.character(max)){
-	command.text<-max
-	max<-eval(parse(text=command.text), envir = parent.frame())
+	max<-.loadServersideObject(max)
 	}
 
 	random.number.vector<-stats::runif(n, min=min, max=max)
diff --git a/R/sampleDS.R b/R/sampleDS.R
index 1c5bd43f..213451dd 100644
--- a/R/sampleDS.R
+++ b/R/sampleDS.R
@@ -30,6 +30,7 @@
 #' 'newobj.sample') which is written to the serverside. For further details see 
 #' help for ds.sample and native R help for sample().
 #' @author Paul Burton, for DataSHIELD Development Team, 15/4/2020
+#' @author Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 #' @export
 sampleDS <- function(x.transmit, size.transmit, replace.transmit=NULL, prob.transmit=NULL){
   
@@ -82,7 +83,7 @@ sampleDS <- function(x.transmit, size.transmit, replace.transmit=NULL, prob.tran
   #Activate <x> and <prob> if they are character strings
   if(is.character(x.transmit))
   {
-      x.active<-eval(parse(text=x.transmit), envir = parent.frame())
+      x.active<-.loadServersideObject(x.transmit)
   
   	if(is.data.frame(x.active)||is.matrix(x.active))
   		{
@@ -152,7 +153,7 @@ sampleDS <- function(x.transmit, size.transmit, replace.transmit=NULL, prob.tran
   prob.active<-NULL
   if(is.character(prob.transmit))
   {
-      prob.active<-eval(parse(text=prob.transmit), envir = parent.frame())
+      prob.active<-.loadServersideObject(prob.transmit)
   }
   
   #Check size <= length(x.active) if replace.transmit==FALSE
diff --git a/R/setSeedDS.R b/R/setSeedDS.R
index 6515d51a..bead37b7 100644
--- a/R/setSeedDS.R
+++ b/R/setSeedDS.R
@@ -32,13 +32,18 @@
 #' .Random.seed on each data source that is the true current state of the
 #' random seed in each source.
 #' @author Paul Burton for DataSHIELD Development Team
+#' @author Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 #' @export
 setSeedDS<-function (seedtext=NULL, kind = NULL, normal.kind = NULL)
 {
     # Check Permissive Privacy Control Level.
     dsBase::checkPermissivePrivacyControlLevel(c('permissive', 'avocado'))
 
-    seed<-eval(parse(text=seedtext), envir = parent.frame())
+    if(is.null(seedtext) || seedtext == "NULL"){
+        seed <- NULL
+    } else {
+        seed <- as.integer(seedtext)
+    }
     set.seed(seed,kind,normal.kind)
     return(list(seed.as.set=.Random.seed))
 }
diff --git a/man/rBinomDS.Rd b/man/rBinomDS.Rd
index 9a3fc25e..b8d16755 100644
--- a/man/rBinomDS.Rd
+++ b/man/rBinomDS.Rd
@@ -42,4 +42,6 @@ the function rbinom() in native R and its arguments are the same.
 }
 \author{
 Paul Burton for DataSHIELD Development Team
+
+Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 }
diff --git a/man/rNormDS.Rd b/man/rNormDS.Rd
index ef7ea58d..f4dd1f4f 100644
--- a/man/rNormDS.Rd
+++ b/man/rNormDS.Rd
@@ -48,4 +48,6 @@ the function rnorm() in native R and its arguments are the same.
 }
 \author{
 Paul Burton for DataSHIELD Development Team
+
+Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 }
diff --git a/man/rPoisDS.Rd b/man/rPoisDS.Rd
index 73fcdee0..9d3d2dbe 100644
--- a/man/rPoisDS.Rd
+++ b/man/rPoisDS.Rd
@@ -37,4 +37,6 @@ and its arguments are the same.
 }
 \author{
 Paul Burton for DataSHIELD Development Team
+
+Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 }
diff --git a/man/rUnifDS.Rd b/man/rUnifDS.Rd
index c9b448ea..f3ad01c8 100644
--- a/man/rUnifDS.Rd
+++ b/man/rUnifDS.Rd
@@ -48,4 +48,6 @@ the function runif() in native R and its arguments are the same.
 }
 \author{
 Paul Burton for DataSHIELD Development Team
+
+Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 }
diff --git a/man/sampleDS.Rd b/man/sampleDS.Rd
index c3d2ead7..aae770f8 100644
--- a/man/sampleDS.Rd
+++ b/man/sampleDS.Rd
@@ -54,4 +54,6 @@ help for ds.sample and native R help for sample().
 }
 \author{
 Paul Burton, for DataSHIELD Development Team, 15/4/2020
+
+Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 }
diff --git a/man/setSeedDS.Rd b/man/setSeedDS.Rd
index 9c8c2740..6531b5f2 100644
--- a/man/setSeedDS.Rd
+++ b/man/setSeedDS.Rd
@@ -50,4 +50,6 @@ theoretical work with random number generators it is likely that the
 }
 \author{
 Paul Burton for DataSHIELD Development Team
+
+Tim Cadman, Genomics Coordination Centre, UMCG, Netherlands
 }
diff --git a/tests/testthat/test-smk-rBinomDS.R b/tests/testthat/test-smk-rBinomDS.R
index 9cff07d0..a25d1a5b 100644
--- a/tests/testthat/test-smk-rBinomDS.R
+++ b/tests/testthat/test-smk-rBinomDS.R
@@ -15,6 +15,8 @@
 
 # context("rBinomDS::smk::setup")
 
+set.standard.disclosure.settings()
+
 #
 # Tests
 #
@@ -58,6 +60,14 @@ test_that("simple rBinomDS, direct", {
     expect_true(res[8] >= 0)
 })
 
+test_that("rBinomDS fails when size references nonexistent object", {
+    expect_error(rBinomDS(8, "nonexistent_obj", 0.5), "does not exist")
+})
+
+test_that("rBinomDS fails when prob references nonexistent object", {
+    expect_error(rBinomDS(8, 1, "nonexistent_obj"), "does not exist")
+})
+
 #
 # Done
 #
diff --git a/tests/testthat/test-smk-rNormDS.R b/tests/testthat/test-smk-rNormDS.R
index 484ef851..0182aab6 100644
--- a/tests/testthat/test-smk-rNormDS.R
+++ b/tests/testthat/test-smk-rNormDS.R
@@ -15,6 +15,8 @@
 
 # context("rNormDS::smk::setup")
 
+set.standard.disclosure.settings()
+
 #
 # Tests
 #
@@ -58,6 +60,14 @@ test_that("simple rNormDS, direct", {
     expect_true(res[8] >= 0)
 })
 
+test_that("rNormDS fails when mean references nonexistent object", {
+    expect_error(rNormDS(8, "nonexistent_obj", 1, 9), "does not exist")
+})
+
+test_that("rNormDS fails when sd references nonexistent object", {
+    expect_error(rNormDS(8, 0, "nonexistent_obj", 9), "does not exist")
+})
+
 #
 # Done
 #
diff --git a/tests/testthat/test-smk-rPoisDS.R b/tests/testthat/test-smk-rPoisDS.R
index c2cf55bf..ee9de700 100644
--- a/tests/testthat/test-smk-rPoisDS.R
+++ b/tests/testthat/test-smk-rPoisDS.R
@@ -15,6 +15,8 @@
 
 # context("rPoisDS::smk::setup")
 
+set.standard.disclosure.settings()
+
 #
 # Tests
 #
@@ -56,6 +58,10 @@ test_that("simple rPoisDS, direct", {
     expect_true(res[8] >= 0)
 })
 
+test_that("rPoisDS fails when lambda references nonexistent object", {
+    expect_error(rPoisDS(8, "nonexistent_obj"), "does not exist")
+})
+
 #
 # Done
 #
diff --git a/tests/testthat/test-smk-rUnifDS.R b/tests/testthat/test-smk-rUnifDS.R
index 87c208c4..7507db16 100644
--- a/tests/testthat/test-smk-rUnifDS.R
+++ b/tests/testthat/test-smk-rUnifDS.R
@@ -15,6 +15,8 @@
 
 # context("rUnifDS::smk::setup")
 
+set.standard.disclosure.settings()
+
 #
 # Tests
 #
@@ -58,6 +60,14 @@ test_that("simple rUnifDS, direct", {
     expect_true(res[8] >= 0)
 })
 
+test_that("rUnifDS fails when min references nonexistent object", {
+    expect_error(rUnifDS(8, "nonexistent_obj", 1, 9), "does not exist")
+})
+
+test_that("rUnifDS fails when max references nonexistent object", {
+    expect_error(rUnifDS(8, 0, "nonexistent_obj", 9), "does not exist")
+})
+
 #
 # Done
 #
diff --git a/tests/testthat/test-smk-sampleDS.R b/tests/testthat/test-smk-sampleDS.R
index e3927518..6fb5cdd9 100644
--- a/tests/testthat/test-smk-sampleDS.R
+++ b/tests/testthat/test-smk-sampleDS.R
@@ -46,6 +46,16 @@ test_that("simple sampleDS", {
     expect_length(res$sampling.order, 16)
 })
 
+test_that("sampleDS fails when x references nonexistent object", {
+    expect_error(sampleDS("nonexistent_obj", 5, FALSE, NULL), "does not exist")
+})
+
+test_that("sampleDS fails when prob references nonexistent object", {
+    x <- c(1:32)
+
+    expect_error(sampleDS("x", 5, FALSE, "nonexistent_obj"), "does not exist")
+})
+
 #
 # Done
 #
diff --git a/tests/testthat/test-smk-setSeedDS.R b/tests/testthat/test-smk-setSeedDS.R
index 0cdbf2e9..0e976bd7 100644
--- a/tests/testthat/test-smk-setSeedDS.R
+++ b/tests/testthat/test-smk-setSeedDS.R
@@ -15,6 +15,8 @@
 
 # context("setSeedDS::smk::setup")
 
+set.standard.disclosure.settings()
+
 #
 # Tests
 #
@@ -32,6 +34,14 @@ test_that("simple setSeedDS", {
     expect_length(res$seed.as.set, 626)
 })
 
+test_that("setSeedDS works with numeric string", {
+    res <- setSeedDS("42", NULL, NULL)
+
+    expect_equal(class(res), "list")
+    expect_length(res, 1)
+    expect_length(res$seed.as.set, 626)
+})
+
 #
 # Done
 #