diff --git a/master_changes.md b/master_changes.md
index 71f88495ba6..d5669c8019e 100644
--- a/master_changes.md
+++ b/master_changes.md
@@ -144,6 +144,7 @@ users)
   * env tests: add regression test for append/prepend operators to empty environment variables [#5925, #5935 @dra27]
   * env.win32: add regression test for handling the empty entry in PATH-like variables [#5926, #5935 @dra27]
   * lint: add W41 examples [#5927 @dra27]
+  * [BUG]: head -c is not posix compliant. Use cut -b instead. [#5989 @madroach]
 
 ### Engine
   * Add `sort` command [#5935 @dra27]
diff --git a/tests/reftests/legacy-git.test b/tests/reftests/legacy-git.test
index b5fc8de5337..d97961af66c 100644
--- a/tests/reftests/legacy-git.test
+++ b/tests/reftests/legacy-git.test
@@ -19,7 +19,7 @@ ARCHIVE=$1; shift
 if [ ! -e "packages/${ARCHIVE}" ]; then ( cd packages && tar czf ${ARCHIVE} ${ARCHIVE%.tar.gz}; ) fi
 MD5=$(openssl md5 packages/${ARCHIVE} | cut -d' ' -f2)
 echo 'src: "http://dev.null" checksum: "'$MD5'"' > REPO/packages/${PKG}/url
-CACHEDIR=REPO/cache/md5/$(echo $MD5 |head -c2)
+CACHEDIR=REPO/cache/md5/$(echo $MD5 |cut -b -2)
 mkdir -p $CACHEDIR
 cp "packages/$ARCHIVE" "$CACHEDIR/$MD5"
 ### : INIT :
diff --git a/tests/reftests/legacy-local.test b/tests/reftests/legacy-local.test
index a2a6047145b..90a052801bf 100644
--- a/tests/reftests/legacy-local.test
+++ b/tests/reftests/legacy-local.test
@@ -7,7 +7,7 @@ ARCHIVE=$1; shift
 if [ ! -e "packages/${ARCHIVE}" ]; then ( cd packages && tar czf ${ARCHIVE} ${ARCHIVE%.tar.gz}; ) fi
 MD5=$(openssl md5 packages/${ARCHIVE} | cut -d' ' -f2)
 echo 'src: "http://dev.null" checksum: "'$MD5'"' > REPO/packages/${PKG}/url
-CACHEDIR=REPO/cache/md5/$(echo $MD5 |head -c2)
+CACHEDIR=REPO/cache/md5/$(echo $MD5 |cut -b -2)
 mkdir -p $CACHEDIR
 cp "packages/$ARCHIVE" "$CACHEDIR/$MD5"
 ### : INIT :