diff --git a/shared.sh b/shared.sh
index d924800..4476f28 100644
--- a/shared.sh
+++ b/shared.sh
@@ -16,8 +16,8 @@ pcre_old_calver='^(?P<major>0|[1-9]\d*)-0{0,1}(?P<minor>0|[0-9]\d*)-R(?P<patch>0
 
 input_errors='false'
 scheme="${scheme:-semver}"
-if [[ "${scheme}" != 'semver' && "${scheme}" != 'calver' ]] ; then
-    echo "🛑 Value of 'scheme' is not valid, choose from 'semver' or 'calver'" 1>&2
+if [[ "${scheme}" != 'semver' && "${scheme}" != 'calver' && "${scheme}" != 'pep440' ]] ; then
+    echo "🛑 Value of 'scheme' is not valid, choose from 'semver', 'calver', or 'pep440'" 1>&2
     input_errors='true'
 fi
 
diff --git a/tests/test_version-increment.bats b/tests/test_version-increment.bats
index 4e15087..52512f0 100644
--- a/tests/test_version-increment.bats
+++ b/tests/test_version-increment.bats
@@ -120,6 +120,23 @@ function init_repo {
     [[ "$output" = *"VERSION=2.0.0"* ]]
 }
 
+@test "increments the major digit correctly (pep440)" {
+    init_repo
+
+    export current_version=1.2.3
+    export scheme="pep440"
+    export increment="major"
+
+    run ../../version-increment.sh
+
+    print_run_info
+    [ "$status" -eq 0 ] &&
+    [[ "$output" = *"MAJOR_VERSION=2"* ]] &&
+    [[ "$output" = *"MINOR_VERSION=0"* ]] &&
+    [[ "$output" = *"PATCH_VERSION=0"* ]] &&
+    [[ "$output" = *"VERSION=2.0.0"* ]]
+}
+
 @test "prefixes with v" {
     init_repo
 
@@ -177,3 +194,19 @@ function init_repo {
     [[ "$output" = *"PRE_RELEASE_LABEL=pre.${short_ref}"* ]]
     [[ "$output" = *"VERSION=1.2.4-pre.${short_ref}"* ]]
 }
+
+@test "appends prerelease information in pep440 compatible way if on a branch and scheme is pep440" {
+    init_repo
+
+    export current_version=10.20.30
+    export scheme="pep440"
+    export GITHUB_REF="refs/heads/super-awesome-python"
+    export short_ref="$(git rev-parse --short HEAD | sed 's/0*//')"
+
+    run ../../version-increment.sh
+
+    print_run_info
+    [ "$status" -eq 0 ] &&
+    [[ "$output" = *"PRE_RELEASE_LABEL=pre.${short_ref}"* ]]
+    [[ "$output" = *"VERSION=10.20.31+pre.${short_ref}"* ]]
+}
diff --git a/version-increment.sh b/version-increment.sh
index 915b1a9..1c91ec4 100755
--- a/version-increment.sh
+++ b/version-increment.sh
@@ -75,7 +75,11 @@ fi
 # add pre-release info to version if not the default branch
 if [[ "${current_ref}" != "refs/heads/${default_branch}" ]] ; then
     pre_release="pre.${git_commit}"
-    new_version="${new_version}-${pre_release}"
+    if [[ "${scheme}" == 'pep440' ]] ; then
+        new_version="${new_version}+${pre_release}"
+    else
+        new_version="${new_version}-${pre_release}"
+    fi
     echo "PRE_RELEASE_LABEL=${pre_release}" >> "${GITHUB_OUTPUT}"
 fi
 
diff --git a/version-lookup.sh b/version-lookup.sh
index 45ed51c..90da3be 100755
--- a/version-lookup.sh
+++ b/version-lookup.sh
@@ -53,6 +53,9 @@ if [[ -z "${current_version:-}" ]] ; then
         semver)
             current_version="0.0.0"
         ;;
+        pep440)
+            current_version="0.0.0"
+        ;;
         calver)
             current_version="$(date '+%Y.%-m.0')"
         ;;