diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 77f2e1d..6be62cd 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -111,8 +111,8 @@ jobs:
         run: |
           if [ -n "$KEY" ]; then
             printf '%s\n' "$KEY" > /tmp/scimesh-sign-key.pem
-            openssl pkeyutl -sign -inkey /tmp/scimesh-sign-key.pem \
-              -in SHA256SUMS.txt -out SHA256SUMS.txt.sig
+            openssl dgst -sign /tmp/scimesh-sign-key.pem \
+              -out SHA256SUMS.txt.sig SHA256SUMS.txt
             echo "signed SHA256SUMS.txt"
           else
             echo "SCIMESH_SIGNING_KEY is not set; releasing without a signature"
diff --git a/install.ps1 b/install.ps1
index 7ede40b..aeeb39d 100644
--- a/install.ps1
+++ b/install.ps1
@@ -81,7 +81,7 @@ if ($env:SCIMESH_SKIP_VERIFY -ne "1") {
             try {
                 Invoke-WebRequest -Uri $SumUrl -OutFile $SumFile
                 Invoke-WebRequest -Uri "$SumUrl.sig" -OutFile $SigFile
-                & $openssl.Source pkeyutl -verify -pubin -inkey $PubFile -sigfile $SigFile -in $SumFile 2>&1 | Out-Null
+                & $openssl.Source dgst -verify $PubFile -signature $SigFile $SumFile 2>&1 | Out-Null
                 if ($LASTEXITCODE -eq 0) {
                     Write-Host "Signature verified (Ed25519)"
                 } else {
diff --git a/install.sh b/install.sh
index 798fd82..adb75a8 100644
--- a/install.sh
+++ b/install.sh
@@ -80,7 +80,7 @@ if [ "${SCIMESH_SKIP_VERIFY:-0}" != "1" ]; then
         && curl -fsSL -o "$SIGFILE" "https://github.com/${REPO}/releases/download/${VERSION}/SHA256SUMS.txt.sig" 2>/dev/null; then
       PUBKEY_FILE=$(mktemp)
       printf '%s\n' '-----BEGIN PUBLIC KEY-----' "$SCIMESH_SIGNING_PUBKEY" '-----END PUBLIC KEY-----' > "$PUBKEY_FILE"
-      if openssl pkeyutl -verify -pubin -inkey "$PUBKEY_FILE" -sigfile "$SIGFILE" -in "$SUMFILE" >/dev/null 2>&1; then
+      if openssl dgst -verify "$PUBKEY_FILE" -signature "$SIGFILE" "$SUMFILE" >/dev/null 2>&1; then
         echo "Signature verified (Ed25519)"
       else
         rm -f "$PUBKEY_FILE" "$SIGFILE" "$SUMFILE" "$TARGET.tmp"