diff --git a/CODE_OF_CONDUCT.md b/CODE_OF_CONDUCT.md
index 7953b39..c32021a 100644
--- a/CODE_OF_CONDUCT.md
+++ b/CODE_OF_CONDUCT.md
@@ -1,4 +1,4 @@
-<!-- SPDX-License-Identifier: PMPL-1.0 -->
+<!-- SPDX-License-Identifier: PMPL-1.0-or-later -->
 # Contributor Covenant Code of Conduct
 
 ## Our Pledge
diff --git a/Mustfile b/Mustfile
index 6a0e4d7..bd54bd5 100644
--- a/Mustfile
+++ b/Mustfile
@@ -1,4 +1,4 @@
-# SPDX-License-Identifier: PMPL-1.0
+# SPDX-License-Identifier: PMPL-1.0-or-later
 # Mustfile - hyperpolymath mandatory checks
 # See: https://github.com/hyperpolymath/mustfile
 
diff --git a/hooks/validate-codeql.sh b/hooks/validate-codeql.sh
index 318f842..c435189 100755
--- a/hooks/validate-codeql.sh
+++ b/hooks/validate-codeql.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# SPDX-License-Identifier: PMPL-1.0
+# SPDX-License-Identifier: PMPL-1.0-or-later
 # Pre-commit hook: Validate CodeQL language matrix matches repo
 set -euo pipefail
 
diff --git a/hooks/validate-permissions.sh b/hooks/validate-permissions.sh
index 0cbae23..50fce4f 100755
--- a/hooks/validate-permissions.sh
+++ b/hooks/validate-permissions.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# SPDX-License-Identifier: PMPL-1.0
+# SPDX-License-Identifier: PMPL-1.0-or-later
 # Pre-commit hook: Validate workflow permissions declarations
 set -euo pipefail
 ERRORS=0
diff --git a/hooks/validate-sha-pins.sh b/hooks/validate-sha-pins.sh
index d4052bc..c6d9913 100755
--- a/hooks/validate-sha-pins.sh
+++ b/hooks/validate-sha-pins.sh
@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# SPDX-License-Identifier: PMPL-1.0
+# SPDX-License-Identifier: PMPL-1.0-or-later
 # Pre-commit hook: Validate GitHub Actions are SHA-pinned
 
 set -euo pipefail
diff --git a/hooks/validate-spdx.sh b/hooks/validate-spdx.sh
index 87421eb..7c5e252 100755
--- a/hooks/validate-spdx.sh
+++ b/hooks/validate-spdx.sh
@@ -1,11 +1,11 @@
 #!/usr/bin/env bash
-# SPDX-License-Identifier: PMPL-1.0
+# SPDX-License-Identifier: PMPL-1.0-or-later
 # Pre-commit hook: Validate SPDX headers in workflow files
 
 set -euo pipefail
 
 ERRORS=0
-SPDX_PATTERN="^# SPDX-License-Identifier:PMPL-1.0
+SPDX_PATTERN="^# SPDX-License-Identifier:PMPL-1.0-or-later
 
 for workflow in .github/workflows/*.yml .github/workflows/*.yaml; do
     [ -f "$workflow" ] || continue
@@ -13,7 +13,7 @@ for workflow in .github/workflows/*.yml .github/workflows/*.yaml; do
     first_line=$(head -n1 "$workflow")
     if ! echo "$first_line" | grep -qE "$SPDX_PATTERN"; then
         echo "ERROR: Missing SPDX header in $workflow"
-        echo "  First line should be: # SPDX-License-Identifier: PMPL-1.0
+        echo "  First line should be: # SPDX-License-Identifier: PMPL-1.0-or-later
         ERRORS=$((ERRORS + 1))
     fi
 done