diff --git a/R/srs.polygon.r b/R/srs.polygon.r
index ccaf720..11a5cba 100644
--- a/R/srs.polygon.r
+++ b/R/srs.polygon.r
@@ -58,11 +58,22 @@
 #' 
 srs.polygon <- function( x, n ){
 
-  #   Check n
+  # Check n
   if( n < 1 ){
     n <- 1
     warning("Sample size less than one has been reset to 1")
   }
+  
+  # Function to convert SpatialPolygons to SpatialPolygonsDataFrame
+  makeSpatialPolygonsDataFrame <- function(x) {
+    x <- SpatialPolygonsDataFrame(x, data.frame(ID=1:length(x)), match.ID=FALSE)
+    return(x)
+  }
+  
+  # Check for SpatialPolygons and convert if needed
+  if(class(x) == "SpatialPolygons") {
+    x <- makeSpatialPolygonsDataFrame(x)
+  }
     
   # Bounding box of shapefile
   bb <- bbox( x )
diff --git a/R/sss.polygon.r b/R/sss.polygon.r
index 73ae986..1923bd7 100644
--- a/R/sss.polygon.r
+++ b/R/sss.polygon.r
@@ -184,6 +184,16 @@
 #' 
 sss.polygon <- function( x, n, spacing=c(1,1), triangular=FALSE, rand.dir=FALSE ){
 
+# Function to convert SpatialPolygons to SpatialPolygonsDataFrame
+makeSpatialPolygonsDataFrame <- function(x) {
+  x <- SpatialPolygonsDataFrame(x, data.frame(ID=1:length(x)), match.ID=FALSE)
+  return(x)
+}
+  
+# Check for SpatialPolygons and convert if needed
+if(class(x) == "SpatialPolygons") {
+  x <- makeSpatialPolygonsDataFrame(x)
+}
 
 #   Bounding box of shapefile
 bb <- bbox( x )
diff --git a/tests/testthat/test-srs.polygon.R b/tests/testthat/test-srs.polygon.R
index 6efc74c..24d19a0 100644
--- a/tests/testthat/test-srs.polygon.R
+++ b/tests/testthat/test-srs.polygon.R
@@ -26,6 +26,15 @@ test_that("warning when sample size less than 1",{
   expect_warning(srs.polygon(WY, 0), "Sample size less than one has been reset to 1")
 })
 
+test_that("check if x is SpatialPolygons", {
+  expect_is(srs.polygon(spatPoly,15), "SpatialPointsDataFrame")
+  expect_type(srs.polygon(spatPoly, 15), "S4")
+})
+
+test_that("check for the column names when none specified", {
+  expect_named(srs.polygon(spatPoly, 15), c("sampleID", "geometryID", "ID"))
+})
+
 test_that("x is a SpatialPointsDataFrame", {
   expect_is(srs.polygon(WY,25), "SpatialPointsDataFrame")
   expect_type(srs.polygon(WY, 20), "S4")
diff --git a/tests/testthat/test-sss.polygon.R b/tests/testthat/test-sss.polygon.R
index 2628022..021d529 100644
--- a/tests/testthat/test-sss.polygon.R
+++ b/tests/testthat/test-sss.polygon.R
@@ -5,6 +5,31 @@ context("Testing sss.polygon()")
 # load pre-built dataset
 data(WY)
 
+# create spatial polygons object
+# make "squares" with integer values rounded in a list
+square <- rbind( c(2, 4, 3, 4, 3, 5,
+                   2, 5, 2, 4, 2, 4),
+                 c(6, 9, 7, 9, 7, 8,
+                   6, 8, 6, 9, 6, 9))
+
+# give these "squares" an identification
+ID <- c("shape1", "shape2")
+
+# create SpatialPolygon object from these squares 
+spatPoly <- SpatialPolygons(list(
+  Polygons(list(Polygon(matrix(square[1, ], ncol = 2, byrow = TRUE))), ID[1]),
+  Polygons(list(Polygon(matrix(square[2, ], ncol = 2, byrow = TRUE))), ID[2])
+))
+
+
+test_that("check if x is SpatialPolygons", {
+  expect_is(sss.polygon(spatPoly,15), "SpatialPointsDataFrame")
+  expect_type(sss.polygon(spatPoly, 15), "S4")
+})
+
+test_that("check for the column names when none specified", {
+  expect_named(sss.polygon(spatPoly, 15), c("sampleID", "row", "col", "geometryID", "ID"))
+})
 
 test_that("check for the column names when none specified", {
   expect_named(sss.polygon(WY, 30), c("sampleID", "row", "col", "geometryID", "STATEFP", "COUNTYFP", "NAME"))