diff --git a/tests/playTests.sh b/tests/playTests.sh
index dfca1de8..6179265e 100755
--- a/tests/playTests.sh
+++ b/tests/playTests.sh
@@ -31,10 +31,10 @@ case "$OS" in
     ;;
 esac
 
-MD5SUM="md5sum"
-if [[ "$OSTYPE" == "darwin"* ]]; then
-    MD5SUM="md5 -r"
-fi
+case "$OSTYPE" in
+  darwin*) MD5SUM="md5 -r" ;;
+  *) MD5SUM="md5sum" ;;
+esac
 
 $ECHO "\nStarting playTests.sh isWindows=$isWindows ZSTD='$ZSTD'"
 
@@ -228,11 +228,10 @@ cp ../programs/*.h dirTestDict
 $MD5SUM dirTestDict/* > tmph1
 $ZSTD -f --rm dirTestDict/* -D tmpDictC
 $ZSTD -d --rm dirTestDict/*.zst -D tmpDictC  # note : use internal checksum by default
-if [[ "$OSTYPE" == "darwin"* ]]; then
-  $ECHO "md5sum -c not supported on OS-X : test skipped"  # not compatible with OS-X's md5
-else
-  $MD5SUM -c tmph1
-fi
+case "$OSTYPE" in
+  darwin*) $ECHO "md5sum -c not supported on OS-X : test skipped" ;;  # not compatible with OS-X's md5
+  *) $MD5SUM -c tmph1 ;;
+esac
 rm -rf dirTestDict
 rm tmp*