diff --git a/processor/processor.go b/processor/processor.go
index 973c448..d284e36 100644
--- a/processor/processor.go
+++ b/processor/processor.go
@@ -599,8 +599,8 @@ func EvalRegex(L *lua.LState) int {
 	if len(matches) > 0 {
 		matchesTable := L.NewTable()
 		for i, match := range matches {
-			matchesTable.RawSetString(fmt.Sprintf("%d", i), lua.LString(match))
-			evalRegexLogger.Debug("Set table[%d] = %q", i, match)
+			matchesTable.RawSetInt(i+1, lua.LString(match))
+			evalRegexLogger.Debug("Set table[%d] = %q", i+1, match)
 		}
 		L.Push(matchesTable)
 	} else {
diff --git a/processor/processor_test.go b/processor/processor_test.go
index 8723b0d..99cfa35 100644
--- a/processor/processor_test.go
+++ b/processor/processor_test.go
@@ -1,7 +1,6 @@
 package processor_test
 
 import (
-	"fmt"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -30,8 +29,8 @@ func TestEvalRegex_CaptureGroupsReturned(t *testing.T) {
 	}
 	expected := []string{"test-42", "test", "42"}
 	for i, v := range expected {
-		val := tbl.RawGetString(fmt.Sprintf("%d", i))
-		assert.Equal(t, lua.LString(v), val, "Expected index %d to be %q", i, v)
+		val := tbl.RawGetInt(i + 1)
+		assert.Equal(t, lua.LString(v), val, "Expected index %d to be %q", i+1, v)
 	}
 }
 
@@ -67,9 +66,9 @@ func TestEvalRegex_NoCaptureGroups(t *testing.T) {
 	if !ok {
 		t.Fatalf("Expected Lua table, got %T", out)
 	}
-	fullMatch := tbl.RawGetString("0")
+	fullMatch := tbl.RawGetInt(1)
 	assert.Equal(t, lua.LString("foo123"), fullMatch)
-	// There should be only the full match (index 0)
+	// There should be only the full match (index 1)
 	count := 0
 	tbl.ForEach(func(k, v lua.LValue) {
 		count++