diff --git a/readme.md b/readme.md
index 0fa11f1..db778e6 100644
--- a/readme.md
+++ b/readme.md
@@ -45,6 +45,7 @@ from various contexts of CA, CI and OCI / OS.
 | SPCD_BRANCH_STAGING | Staging deployment branch | dev                             |
 | SPCD_BRANCH_FEATURE | Feature deployment branch | f                               |
 | SPCD_CA_n           | Numbered CA certificates  |                                 |
+| SPCD_CMD_SUM        | Command to check sums     | sha512sum                       |
 | SPCD_DNS_n          | Numbered name servers     | 9.9.9.9                         |
 | SPCD_GIT_MAIN       | Main Git repository       | spcd                            |
 | SPCD_GIT_ROOT       | Root Git repository       | rwx                             |
@@ -87,7 +88,15 @@ from various contexts of CA, CI and OCI / OS.
 * relay environment module name
 * write tests
 
-### .py
+### sh
+
+* support opensuse
+
+### sh → py
+
+* check file & variable sums
+
+### py
 
 * detect ssh private key type
 * implement project repository cloning
@@ -102,7 +111,3 @@ from various contexts of CA, CI and OCI / OS.
 * lint
   * .py
   * .sh
-
-### .sh
-
-* support opensuse
diff --git a/spcd.sh b/spcd.sh
index ad425f4..24d6d2e 100644
--- a/spcd.sh
+++ b/spcd.sh
@@ -4,6 +4,7 @@
 [ -n "${SPCD_BRANCH_RELEASE}" ] || SPCD_BRANCH_RELEASE="main"
 [ -n "${SPCD_BRANCH_STAGING}" ] || SPCD_BRANCH_STAGING="dev"
 [ -n "${SPCD_BRANCH_FEATURE}" ] || SPCD_BRANCH_FEATURE="f"
+[ -n "${SPCD_CMD_SUM}" ] || SPCD_CMD_SUM="sha512sum"
 [ -n "${SPCD_DNS_1}" ] || SPCD_DNS_1="9.9.9.9"
 [ -n "${SPCD_GIT_MAIN}" ] || SPCD_GIT_MAIN="spcd"
 [ -n "${SPCD_GIT_ROOT}" ] || SPCD_GIT_ROOT="rwx"
@@ -661,13 +662,13 @@ ${spcd_ipm__target}"
         spcd_ipm__script="${spcd_ipm__root}/${spcd_ipm__name}/spcd.sh"
         if [ -f "${spcd_ipm__script}" ]; then
             spcd_split
-            spcd_ipm__check="${spcd_ipm__root}/check.sha512sum"
-            sha512sum "${spcd_ipm__script}" >"${spcd_ipm__check}"
+            spcd_ipm__check="${spcd_ipm__root}/check.${SPCD_CMD_SUM}"
+            "${SPCD_CMD_SUM}" "${spcd_ipm__script}" >"${spcd_ipm__check}"
             printf "%s" "${SPCD}" >"${spcd_ipm__script}"
             ls -l "${spcd_ipm__script}"
             dos2unix "${spcd_ipm__script}"
             ls -l "${spcd_ipm__script}"
-            sha512sum -c "${spcd_ipm__check}" || spcd_error_ci "SPCD"
+            "${SPCD_CMD_SUM}" -c "${spcd_ipm__check}" || spcd_error_ci "SPCD"
         fi
     done
     spcd_split