diff --git a/main.go b/main.go
index dac0c57c0..886a7d955 100644
--- a/main.go
+++ b/main.go
@@ -538,6 +538,13 @@ func main() {
 		"start as an MCP (Model Context Protocol) server over stdio",
 	)
 
+	flags.StringVar(
+		&processor.LanguagesFile,
+		"languages-file",
+		"",
+		"path to a custom languages.json file to augment or override built-in languages",
+	)
+
 	// If invoked in the format of "scc completion --shell [name of shell]", generate command line completions instead.
 	// With the --shell option, unintentionally triggering shell completions should be highly unlikely.
 	args := os.Args
diff --git a/processor/processor.go b/processor/processor.go
index 724d82f5f..7471e70d7 100644
--- a/processor/processor.go
+++ b/processor/processor.go
@@ -3,6 +3,7 @@
 package processor
 
 import (
+	"encoding/json"
 	"fmt"
 	"io"
 	"os"
@@ -146,6 +147,9 @@ var RemapUnknown = ""
 // RemapAll allows remapping of all files with a string to search the content for
 var RemapAll = ""
 
+// LanguagesFile is the path to a custom languages.json file
+var LanguagesFile = ""
+
 type remapRule struct {
 	pattern  []byte
 	language string
@@ -324,6 +328,21 @@ func ConfigureLazy(lazy bool) {
 // Needs to be called at least once in order for anything to actually happen
 func ProcessConstants() {
 	startTime := makeTimestampNano()
+	if LanguagesFile != "" {
+		data, err := os.ReadFile(LanguagesFile)
+		if err != nil {
+			printError("failed to read languages file: " + err.Error())
+		} else {
+			var customLanguages map[string]Language
+			if err := json.Unmarshal(data, &customLanguages); err != nil {
+				printError("failed to parse languages file: " + err.Error())
+			} else {
+				for name, lang := range customLanguages {
+					languageDatabase[name] = lang
+				}
+			}
+		}
+	}
 	for name, value := range languageDatabase {
 		for _, ext := range value.Extensions {
 			ExtensionToLanguage[ext] = append(ExtensionToLanguage[ext], name)
diff --git a/processor/processor_test.go b/processor/processor_test.go
index b469ff5d7..2b11ca9df 100644
--- a/processor/processor_test.go
+++ b/processor/processor_test.go
@@ -3,6 +3,9 @@
 package processor
 
 import (
+	"encoding/json"
+	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 )
@@ -154,3 +157,24 @@ func TestSetupCountAsMultiple(t *testing.T) {
 
 	CountAs = ""
 }
+func TestLanguagesFileIsValidJSON(t *testing.T) {
+	data, err := os.ReadFile("../languages.json")
+	if err != nil {
+		t.Fatal("failed to read languages.json", err)
+	}
+
+	var languages map[string]Language
+	if err := json.Unmarshal(data, &languages); err != nil {
+		t.Error("languages.json is not valid JSON", err)
+	}
+}
+
+func TestLanguagesFileInvalidJSON(t *testing.T) {
+	dir, _ := os.MkdirTemp("", "test-languages")
+	langFile := filepath.Join(dir, "languages.json")
+	_ = os.WriteFile(langFile, []byte(`not valid json`), 0644)
+
+	LanguagesFile = langFile
+	// should not panic
+	ProcessConstants()
+}