diff --git a/R/terra_gdal_calc.R b/R/terra_gdal_calc.R
index fac83ed7..1958fdef 100644
--- a/R/terra_gdal_calc.R
+++ b/R/terra_gdal_calc.R
@@ -253,7 +253,7 @@ terra_gdal_calc <- function(x, expr,
     file.exists(filename),
     msg = paste0(
       "failed to run `gdal_calc.py` script: output file \"",
-      filename, "\ does not exist"
+      filename, "\" does not exist"
     )
   )
 
diff --git a/tests/testthat/test_create_spp_aoh_data.R b/tests/testthat/test_create_spp_aoh_data.R
index 6e4dcb88..3648565a 100644
--- a/tests/testthat/test_create_spp_aoh_data.R
+++ b/tests/testthat/test_create_spp_aoh_data.R
@@ -87,6 +87,7 @@ test_that("simulated data (GDAL engine)", {
   skip_on_cran()
   skip_if_not_installed("gdalUtilities")
   skip_if_gdal_calc_not_available()
+  skip_on_os("mac")
   # specify file path
   f <- system.file("testdata", "SIMULATED_SPECIES.zip", package = "aoh")
   elevation_data <- terra::rast(
@@ -549,6 +550,7 @@ test_that("small range data (rasterize_touches, engine = gdal)", {
   skip_on_cran()
   skip_if_not_installed("gdalUtilities")
   skip_if_gdal_calc_not_available()
+  skip_on_os("mac")
   # specify file path
   f <- system.file("testdata", "SIMULATED_SPECIES.zip", package = "aoh")
   elevation_data <- terra::rast(
diff --git a/tests/testthat/test_create_spp_frc_data.R b/tests/testthat/test_create_spp_frc_data.R
index 358050b6..0b1287d8 100644
--- a/tests/testthat/test_create_spp_frc_data.R
+++ b/tests/testthat/test_create_spp_frc_data.R
@@ -66,7 +66,8 @@ test_that("different engines produce same result", {
   # skip if needed
   skip_on_cran()
   skip_if_not_installed("gdalUtilities")
-  skip_if_gdal_calc_not_available()
+  skip_if_gdal_calc_not_available()\
+  skip_on_os("mac")
   # specify file path
   f <- system.file("testdata", "SIMULATED_SPECIES.zip", package = "aoh")
   elevation_data <- terra::rast(
diff --git a/tests/testthat/test_terra_gdal_calc.R b/tests/testthat/test_terra_gdal_calc.R
index 45ea08f7..4d6ed5de 100644
--- a/tests/testthat/test_terra_gdal_calc.R
+++ b/tests/testthat/test_terra_gdal_calc.R
@@ -4,6 +4,7 @@ test_that("single layer (in memory)", {
   skip_on_cran()
   skip_if_not_installed("gdalUtilities")
   skip_if_gdal_calc_not_available()
+  skip_on_os("mac")
   # create data
   x <- terra::rast(
    ncols = 40, nrows = 40, xmin = -110, xmax = -90, ymin = 40, ymax = 60,
@@ -23,6 +24,7 @@ test_that("two layers", {
   skip_on_cran()
   skip_if_not_installed("gdalUtilities")
   skip_if_gdal_calc_not_available()
+  skip_on_os("mac")
   # create data
   x <- terra::rast(
    ncols = 40, nrows = 40, xmin = -110, xmax = -90, ymin = 40, ymax = 60,
@@ -43,6 +45,7 @@ test_that("three layers (in memory)", {
   skip_on_cran()
   skip_if_not_installed("gdalUtilities")
   skip_if_gdal_calc_not_available()
+  skip_on_os("mac")
   # create data
   x <- terra::rast(
    ncols = 40, nrows = 40, xmin = -110, xmax = -90, ymin = 40, ymax = 60,
@@ -66,6 +69,7 @@ test_that("three layers (on disk)", {
   skip_on_cran()
   skip_if_not_installed("gdalUtilities")
   skip_if_gdal_calc_not_available()
+  skip_on_os("mac")
   # create paths
   f1 <- tempfile(fileext = ".tif")
   f2 <- tempfile(fileext = ".tif")