diff --git a/internal/cli/modify.go b/internal/cli/modify.go
index 31ab7805..dfeaa5a6 100644
--- a/internal/cli/modify.go
+++ b/internal/cli/modify.go
@@ -42,6 +42,7 @@ Modify the registration data of library name LIBRARY_NAME according to the FLAGs
 
 func init() {
 	modifyCmd.Flags().String("repo-url", "", "New library repository URL")
+	modifyCmd.Flags().String("types", "", "New types list for the library's releases (comma separated)")
 
 	rootCmd.AddCommand(modifyCmd)
 }
diff --git a/internal/command/modify/modify.go b/internal/command/modify/modify.go
index d80245af..a21315a7 100644
--- a/internal/command/modify/modify.go
+++ b/internal/command/modify/modify.go
@@ -27,6 +27,7 @@ package modify
 import (
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/arduino/go-paths-helper"
 	"github.com/arduino/libraries-repository-engine/internal/backup"
@@ -121,6 +122,10 @@ func modifications(flags *pflag.FlagSet) (bool, error) {
 	if err != nil {
 		return false, err
 	}
+	newTypes, err := flags.GetString("types")
+	if err != nil {
+		return false, err
+	}
 
 	if newRepositoryURL != "" {
 		if err := modifyRepositoryURL(newRepositoryURL); err != nil {
@@ -130,6 +135,14 @@ func modifications(flags *pflag.FlagSet) (bool, error) {
 		didModify = true
 	}
 
+	if newTypes != "" {
+		if err := modifyTypes(newTypes); err != nil {
+			return false, err
+		}
+
+		didModify = true
+	}
+
 	if !didModify {
 		return false, fmt.Errorf("No modification flags provided so nothing happened. See 'libraries-repository-engine modify --help'")
 	}
@@ -215,3 +228,48 @@ func modifyRepositoryURL(newRepositoryURL string) error {
 
 	return nil
 }
+
+func modifyTypes(rawTypes string) error {
+	newTypes := strings.Split(rawTypes, ",")
+	for i := range newTypes {
+		newTypes[i] = strings.TrimSpace(newTypes[i])
+	}
+
+	sameTypes := func(oldTypes []string) bool {
+		if len(oldTypes) != len(newTypes) {
+			return false
+		}
+
+		for _, oldType := range oldTypes {
+			found := false
+			for _, newType := range newTypes {
+				if oldType == newType {
+					found = true
+					break
+				}
+			}
+			if !found {
+				return false
+			}
+		}
+
+		return true
+	}
+
+	typesChanged := false
+
+	for _, releaseData := range releasesData {
+		if !typesChanged {
+			// Compare old and new types for this release
+			typesChanged = !sameTypes(releaseData.Types)
+		}
+
+		releaseData.Types = newTypes
+	}
+
+	if !typesChanged {
+		return fmt.Errorf("Library %s already has types %s", libraryName, rawTypes)
+	}
+
+	return nil
+}
diff --git a/test/test_modify.py b/test/test_modify.py
index a434022b..f6ef6b64 100644
--- a/test/test_modify.py
+++ b/test/test_modify.py
@@ -333,3 +333,65 @@ def get_release_archive_url(name, version):
         )
     assert canary_release_archive_path.exists()
     assert get_release_archive_url(name=canary_name, version=canary_release) == canary_release_archive_url
+
+
+def test_types(configuration, run_command):
+    """Test the `--types` modification flag in action."""
+    name = "SpacebrewYun"
+    raw_old_types = "Arduino"
+    raw_new_types = "Arduino, Retired"
+    canary_name = "Arduino Uno WiFi Dev Ed Library"
+    raw_canary_types = "Partner"
+    # Run the sync command to generate test data
+    engine_command = [
+        "sync",
+        "--config-file",
+        configuration.path,
+        test_data_path.joinpath("test_modify", "test_types", "repos.txt"),
+    ]
+    result = run_command(cmd=engine_command)
+    assert result.ok
+    assert pathlib.Path(configuration.data["LibrariesDB"]).exists()
+
+    def assert_types(name, raw_types):
+        with pathlib.Path(configuration.data["LibrariesDB"]).open(mode="r", encoding="utf-8") as library_db_file:
+            library_db = json.load(fp=library_db_file)
+        for release in library_db["Releases"]:
+            if release["LibraryName"] == name and release["Types"] != [
+                raw_type.strip() for raw_type in raw_types.split(sep=",")
+            ]:
+                return False
+        return True
+
+    # Verify the pre-command DB is as expected
+    assert assert_types(name=name, raw_types=raw_old_types)
+    assert assert_types(name=canary_name, raw_types=raw_canary_types)
+
+    # Run the modification command with existing types
+    engine_command = [
+        "modify",
+        "--config-file",
+        configuration.path,
+        "--types",
+        raw_old_types,
+        name,
+    ]
+    result = run_command(cmd=engine_command)
+    assert not result.ok
+    assert f"{name} already has types {raw_old_types}" in result.stderr
+
+    # Run the modification command with existing types
+    engine_command = [
+        "modify",
+        "--config-file",
+        configuration.path,
+        "--types",
+        raw_new_types,
+        name,
+    ]
+    result = run_command(cmd=engine_command)
+    assert result.ok
+
+    # Verify the effect of the command was as expected
+    assert assert_types(name=name, raw_types=raw_new_types)
+    assert assert_types(name=canary_name, raw_types=raw_canary_types)
diff --git a/test/testdata/test_modify/test_types/repos.txt b/test/testdata/test_modify/test_types/repos.txt
new file mode 100644
index 00000000..c35693c1
--- /dev/null
+++ b/test/testdata/test_modify/test_types/repos.txt
@@ -0,0 +1,2 @@
+https://github.com/arduino-libraries/SpacebrewYun.git|Arduino|SpacebrewYun
+https://github.com/arduino-libraries/UnoWiFi-Developer-Edition-Lib.git|Partner|Arduino Uno WiFi Dev Ed Library