diff --git a/tests/test_swtpm_cert b/tests/test_swtpm_cert
index ad4e4f91..4b095ee5 100755
--- a/tests/test_swtpm_cert
+++ b/tests/test_swtpm_cert
@@ -24,7 +24,7 @@ function check_cert_size()
 
 	local size
 
-	size=$(stat -c%s "${cert}" 2>/dev/null)
+	size=$(get_filesize "${cert}")
 	if [ "$size" -ne "$exp" ]; then
 		echo "Warning: Certificate file has unexpected size."
 		echo "         Expected: $exp;  found: $size"
diff --git a/tests/test_tpm2_swtpm_cert b/tests/test_tpm2_swtpm_cert
index 3fc3215a..36775041 100755
--- a/tests/test_tpm2_swtpm_cert
+++ b/tests/test_tpm2_swtpm_cert
@@ -24,7 +24,7 @@ function check_cert_size()
 
 	local size
 
-	size=$(stat -c%s "${cert}" 2>/dev/null)
+	size=$(get_filesize "${cert}")
 	if [ "$size" -ne "$exp" ]; then
 		echo "Warning: Certificate file has unexpected size."
 		echo "         Expected: $exp;  found: $size"
diff --git a/tests/test_tpm2_swtpm_cert_ecc b/tests/test_tpm2_swtpm_cert_ecc
index 6006e85a..baf2848f 100755
--- a/tests/test_tpm2_swtpm_cert_ecc
+++ b/tests/test_tpm2_swtpm_cert_ecc
@@ -24,7 +24,7 @@ function check_cert_size()
 
 	local size
 
-	size=$(stat -c%s "${cert}" 2>/dev/null)
+	size=$(get_filesize "${cert}")
 	if [ "$size" -ne "$exp" ]; then
 		echo "Warning: Certificate file has unexpected size."
 		echo "         Expected: $exp;  found: $size"