diff --git a/backend/tests/test_bmp.c b/backend/tests/test_bmp.c
index 6cd6fd43..76508479 100644
--- a/backend/tests/test_bmp.c
+++ b/backend/tests/test_bmp.c
@@ -231,6 +231,7 @@ static void test_print(const testCtx *const p_ctx) {
 
 static void test_outfile(const testCtx *const p_ctx) {
     int ret;
+    int skip_readonly_test = 0;
     struct zint_symbol symbol = {0};
     unsigned char data[] = { "1" };
 
@@ -243,12 +244,17 @@ static void test_outfile(const testCtx *const p_ctx) {
     symbol.bitmap_width = symbol.bitmap_height = 1;
 
     strcpy(symbol.outfile, "test_bmp_out.bmp");
-    (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
-    assert_nonzero(testUtilCreateROFile(symbol.outfile), "bmp_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+#ifndef _WIN32
+    skip_readonly_test = getuid() == 0; /* Skip if running as root on Unix as can't create read-only file */
+#endif
+    if (!skip_readonly_test) {
+        (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
+        assert_nonzero(testUtilCreateROFile(symbol.outfile), "bmp_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
 
-    ret = bmp_pixel_plot(&symbol, data);
-    assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "bmp_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
-    assert_zero(testUtilRmROFile(symbol.outfile), "bmp_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+        ret = bmp_pixel_plot(&symbol, data);
+        assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "bmp_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
+        assert_zero(testUtilRmROFile(symbol.outfile), "bmp_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+    }
 
     symbol.output_options |= BARCODE_STDOUT;
 
diff --git a/backend/tests/test_emf.c b/backend/tests/test_emf.c
index be931d74..43b6b49e 100644
--- a/backend/tests/test_emf.c
+++ b/backend/tests/test_emf.c
@@ -178,6 +178,7 @@ INTERNAL int emf_plot(struct zint_symbol *symbol, int rotate_angle);
 
 static void test_outfile(const testCtx *const p_ctx) {
     int ret;
+    int skip_readonly_test = 0;
     struct zint_symbol symbol = {0};
     struct zint_vector vector = {0};
 
@@ -189,12 +190,17 @@ static void test_outfile(const testCtx *const p_ctx) {
     symbol.vector = &vector;
 
     strcpy(symbol.outfile, "test_emf_out.emf");
-    (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
-    assert_nonzero(testUtilCreateROFile(symbol.outfile), "emf_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+#ifndef _WIN32
+    skip_readonly_test = getuid() == 0; /* Skip if running as root on Unix as can't create read-only file */
+#endif
+    if (!skip_readonly_test) {
+        (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
+        assert_nonzero(testUtilCreateROFile(symbol.outfile), "emf_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
 
-    ret = emf_plot(&symbol, 0);
-    assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "emf_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
-    assert_zero(testUtilRmROFile(symbol.outfile), "emf_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+        ret = emf_plot(&symbol, 0);
+        assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "emf_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
+        assert_zero(testUtilRmROFile(symbol.outfile), "emf_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+    }
 
     symbol.output_options |= BARCODE_STDOUT;
 
diff --git a/backend/tests/test_gif.c b/backend/tests/test_gif.c
index e990f9f1..d4033da2 100644
--- a/backend/tests/test_gif.c
+++ b/backend/tests/test_gif.c
@@ -271,6 +271,7 @@ static void test_print(const testCtx *const p_ctx) {
 
 static void test_outfile(const testCtx *const p_ctx) {
     int ret;
+    int skip_readonly_test = 0;
     struct zint_symbol symbol = {0};
     unsigned char data[] = { "1" };
 
@@ -283,12 +284,17 @@ static void test_outfile(const testCtx *const p_ctx) {
     symbol.bitmap_width = symbol.bitmap_height = 1;
 
     strcpy(symbol.outfile, "test_gif_out.gif");
-    (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
-    assert_nonzero(testUtilCreateROFile(symbol.outfile), "gif_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+#ifndef _WIN32
+    skip_readonly_test = getuid() == 0; /* Skip if running as root on Unix as can't create read-only file */
+#endif
+    if (!skip_readonly_test) {
+        (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
+        assert_nonzero(testUtilCreateROFile(symbol.outfile), "gif_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
 
-    ret = gif_pixel_plot(&symbol, data);
-    assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "gif_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
-    assert_zero(testUtilRmROFile(symbol.outfile), "gif_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+        ret = gif_pixel_plot(&symbol, data);
+        assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "gif_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
+        assert_zero(testUtilRmROFile(symbol.outfile), "gif_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+    }
 
     symbol.output_options |= BARCODE_STDOUT;
 
diff --git a/backend/tests/test_pcx.c b/backend/tests/test_pcx.c
index 60032db8..d382233f 100644
--- a/backend/tests/test_pcx.c
+++ b/backend/tests/test_pcx.c
@@ -146,6 +146,7 @@ INTERNAL int pcx_pixel_plot(struct zint_symbol *symbol, unsigned char *pixelbuf)
 
 static void test_outfile(const testCtx *const p_ctx) {
     int ret;
+    int skip_readonly_test = 0;
     struct zint_symbol symbol = {0};
     unsigned char data[] = { "1" };
 
@@ -158,12 +159,17 @@ static void test_outfile(const testCtx *const p_ctx) {
     symbol.bitmap_width = symbol.bitmap_height = 1;
 
     strcpy(symbol.outfile, "test_pcx_out.pcx");
-    (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
-    assert_nonzero(testUtilCreateROFile(symbol.outfile), "pcx_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+#ifndef _WIN32
+    skip_readonly_test = getuid() == 0; /* Skip if running as root on Unix as can't create read-only file */
+#endif
+    if (!skip_readonly_test) {
+        (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
+        assert_nonzero(testUtilCreateROFile(symbol.outfile), "pcx_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
 
-    ret = pcx_pixel_plot(&symbol, data);
-    assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "pcx_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
-    assert_zero(testUtilRmROFile(symbol.outfile), "pcx_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+        ret = pcx_pixel_plot(&symbol, data);
+        assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "pcx_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
+        assert_zero(testUtilRmROFile(symbol.outfile), "pcx_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+    }
 
     symbol.output_options |= BARCODE_STDOUT;
 
diff --git a/backend/tests/test_png.c b/backend/tests/test_png.c
index 390d8bb3..5eb8bedf 100644
--- a/backend/tests/test_png.c
+++ b/backend/tests/test_png.c
@@ -310,6 +310,7 @@ static void test_print(const testCtx *const p_ctx) {
 
 static void test_outfile(const testCtx *const p_ctx) {
     int ret;
+    int skip_readonly_test = 0;
     struct zint_symbol symbol = {0};
     unsigned char data[] = { "1" };
 
@@ -322,12 +323,17 @@ static void test_outfile(const testCtx *const p_ctx) {
     symbol.bitmap_width = symbol.bitmap_height = 1;
 
     strcpy(symbol.outfile, "test_png_out.png");
-    (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
-    assert_nonzero(testUtilCreateROFile(symbol.outfile), "png_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+#ifndef _WIN32
+    skip_readonly_test = getuid() == 0; /* Skip if running as root on Unix as can't create read-only file */
+#endif
+    if (!skip_readonly_test) {
+        (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
+        assert_nonzero(testUtilCreateROFile(symbol.outfile), "png_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
 
-    ret = png_pixel_plot(&symbol, data);
-    assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "png_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
-    assert_zero(testUtilRmROFile(symbol.outfile), "png_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+        ret = png_pixel_plot(&symbol, data);
+        assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "png_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
+        assert_zero(testUtilRmROFile(symbol.outfile), "png_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+    }
 
     symbol.output_options |= BARCODE_STDOUT;
 
diff --git a/backend/tests/test_ps.c b/backend/tests/test_ps.c
index a9154bc1..c5d114bd 100644
--- a/backend/tests/test_ps.c
+++ b/backend/tests/test_ps.c
@@ -214,6 +214,7 @@ INTERNAL int ps_plot(struct zint_symbol *symbol, int rotate_angle);
 
 static void test_outfile(const testCtx *const p_ctx) {
     int ret;
+    int skip_readonly_test = 0;
     struct zint_symbol symbol = {0};
     struct zint_vector vector = {0};
 
@@ -225,12 +226,17 @@ static void test_outfile(const testCtx *const p_ctx) {
     symbol.vector = &vector;
 
     strcpy(symbol.outfile, "test_ps_out.eps");
-    (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
-    assert_nonzero(testUtilCreateROFile(symbol.outfile), "ps_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+#ifndef _WIN32
+    skip_readonly_test = getuid() == 0; /* Skip if running as root on Unix as can't create read-only file */
+#endif
+    if (!skip_readonly_test) {
+        (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
+        assert_nonzero(testUtilCreateROFile(symbol.outfile), "ps_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
 
-    ret = ps_plot(&symbol, 0);
-    assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "ps_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
-    assert_zero(testUtilRmROFile(symbol.outfile), "ps_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+        ret = ps_plot(&symbol, 0);
+        assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "ps_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
+        assert_zero(testUtilRmROFile(symbol.outfile), "ps_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+    }
 
     symbol.output_options |= BARCODE_STDOUT;
 
diff --git a/backend/tests/test_svg.c b/backend/tests/test_svg.c
index 9ba33b43..f794798c 100644
--- a/backend/tests/test_svg.c
+++ b/backend/tests/test_svg.c
@@ -222,6 +222,7 @@ INTERNAL int svg_plot(struct zint_symbol *symbol, int rotate_angle);
 
 static void test_outfile(const testCtx *const p_ctx) {
     int ret;
+    int skip_readonly_test = 0;
     struct zint_symbol symbol = {0};
     struct zint_vector vector = {0};
 
@@ -233,12 +234,17 @@ static void test_outfile(const testCtx *const p_ctx) {
     symbol.vector = &vector;
 
     strcpy(symbol.outfile, "test_svg_out.svg");
-    (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
-    assert_nonzero(testUtilCreateROFile(symbol.outfile), "svg_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+#ifndef _WIN32
+    skip_readonly_test = getuid() == 0; /* Skip if running as root on Unix as can't create read-only file */
+#endif
+    if (!skip_readonly_test) {
+        (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
+        assert_nonzero(testUtilCreateROFile(symbol.outfile), "svg_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
 
-    ret = svg_plot(&symbol, 0);
-    assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "svg_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
-    assert_zero(testUtilRmROFile(symbol.outfile), "svg_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+        ret = svg_plot(&symbol, 0);
+        assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "svg_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
+        assert_zero(testUtilRmROFile(symbol.outfile), "svg_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+    }
 
     symbol.output_options |= BARCODE_STDOUT;
 
diff --git a/backend/tests/test_tif.c b/backend/tests/test_tif.c
index 9bdf81c6..a9426c95 100644
--- a/backend/tests/test_tif.c
+++ b/backend/tests/test_tif.c
@@ -309,6 +309,7 @@ static void test_print(const testCtx *const p_ctx) {
 
 static void test_outfile(const testCtx *const p_ctx) {
     int ret;
+    int skip_readonly_test = 0;
     struct zint_symbol symbol = {0};
     unsigned char data[] = { "1" };
 
@@ -321,12 +322,17 @@ static void test_outfile(const testCtx *const p_ctx) {
     symbol.bitmap_width = symbol.bitmap_height = 1;
 
     strcpy(symbol.outfile, "test_tif_out.tif");
-    (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
-    assert_nonzero(testUtilCreateROFile(symbol.outfile), "tif_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+#ifndef _WIN32
+    skip_readonly_test = getuid() == 0; /* Skip if running as root on Unix as can't create read-only file */
+#endif
+    if (!skip_readonly_test) {
+        (void) testUtilRmROFile(symbol.outfile); /* In case lying around from previous fail */
+        assert_nonzero(testUtilCreateROFile(symbol.outfile), "tif_pixel_plot testUtilCreateROFile(%s) fail (%d: %s)\n", symbol.outfile, errno, strerror(errno));
 
-    ret = tif_pixel_plot(&symbol, data);
-    assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "tif_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
-    assert_zero(testUtilRmROFile(symbol.outfile), "tif_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+        ret = tif_pixel_plot(&symbol, data);
+        assert_equal(ret, ZINT_ERROR_FILE_ACCESS, "tif_pixel_plot ret %d != ZINT_ERROR_FILE_ACCESS (%d) (%s)\n", ret, ZINT_ERROR_FILE_ACCESS, symbol.errtxt);
+        assert_zero(testUtilRmROFile(symbol.outfile), "tif_pixel_plot testUtilRmROFile(%s) != 0 (%d: %s)\n", symbol.outfile, errno, strerror(errno));
+    }
 
     symbol.output_options |= BARCODE_STDOUT;