diff --git a/api/internal/generators/configmap.go b/api/internal/generators/configmap.go
index 47498aaa58..2f322f7dd3 100644
--- a/api/internal/generators/configmap.go
+++ b/api/internal/generators/configmap.go
@@ -37,7 +37,7 @@ func MakeConfigMap(
 	if err != nil {
 		return nil, err
 	}
-	if err = rn.LoadMapIntoConfigMapData(m); err != nil {
+	if err = rn.LoadMapIntoConfigMapData(m.values); err != nil {
 		return nil, err
 	}
 	err = copyLabelsAndAnnotations(rn, args.Options)
diff --git a/api/internal/generators/secret.go b/api/internal/generators/secret.go
index 9afaff156a..6a6ef8f68f 100644
--- a/api/internal/generators/secret.go
+++ b/api/internal/generators/secret.go
@@ -50,7 +50,7 @@ func MakeSecret(
 	if err != nil {
 		return nil, err
 	}
-	if err = rn.LoadMapIntoSecretData(m); err != nil {
+	if err = rn.LoadMapIntoSecretData(m.values); err != nil {
 		return nil, err
 	}
 	copyLabelsAndAnnotations(rn, args.Options)
diff --git a/api/internal/generators/utils.go b/api/internal/generators/utils.go
index b570c7e91b..6368a2d468 100644
--- a/api/internal/generators/utils.go
+++ b/api/internal/generators/utils.go
@@ -36,25 +36,33 @@ kind: %s
 	return rn, nil
 }
 
+type orderedMap struct {
+	keys   []string
+	values map[string]string
+}
+
 func makeValidatedDataMap(
-	ldr ifc.KvLoader, name string, sources types.KvPairSources) (map[string]string, error) {
+	ldr ifc.KvLoader, name string, sources types.KvPairSources,
+) (orderedMap, error) {
 	pairs, err := ldr.Load(sources)
 	if err != nil {
-		return nil, errors.WrapPrefix(err, "loading KV pairs", 0)
+		return orderedMap{}, errors.WrapPrefix(err, fmt.Sprintf("loading KV pairs, name: %s", name), 0)
 	}
-	knownKeys := make(map[string]string)
+
+	seen := make(map[string]struct{})
+	values := make(map[string]string, len(pairs))
+	keys := make([]string, len(pairs))
+
 	for _, p := range pairs {
-		// legal key: alphanumeric characters, '-', '_' or '.'
 		if err := ldr.Validator().ErrIfInvalidKey(p.Key); err != nil {
-			return nil, err
-		}
-		if _, ok := knownKeys[p.Key]; ok {
-			return nil, errors.Errorf(
-				"configmap %s illegally repeats the key `%s`", name, p.Key)
+			return orderedMap{}, errors.WrapPrefix(err, fmt.Sprintf("invalid key %s, name %s", p.Key, name), 0)
 		}
-		knownKeys[p.Key] = p.Value
+		seen[p.Key] = struct{}{}
+		keys = append(keys, p.Key)
+		values[p.Key] = p.Value
 	}
-	return knownKeys, nil
+
+	return orderedMap{keys: keys, values: values}, nil
 }
 
 // copyLabelsAndAnnotations copies labels and annotations from
diff --git a/api/internal/generators/utils_test.go b/api/internal/generators/utils_test.go
index fbb2f262cf..77776f6ed2 100644
--- a/api/internal/generators/utils_test.go
+++ b/api/internal/generators/utils_test.go
@@ -1,13 +1,15 @@
 // Copyright 2020 The Kubernetes Authors.
 // SPDX-License-Identifier: Apache-2.0
 
-package generators_test
+package generators
 
 import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
-	. "sigs.k8s.io/kustomize/api/internal/generators"
+	"sigs.k8s.io/kustomize/api/ifc"
+	valtest_test "sigs.k8s.io/kustomize/api/testutils/valtest"
+	"sigs.k8s.io/kustomize/api/types"
 )
 
 func TestParseFileSource(t *testing.T) {
@@ -49,3 +51,101 @@ func TestParseFileSource(t *testing.T) {
 		})
 	}
 }
+
+func TestMakeValidateDataMapOrder(t *testing.T) {
+	tests := []struct {
+		name        string
+		pairs       []types.Pair
+		wantKeys    []string
+		wantValues  map[string]string
+		wantErr     bool
+		validatorFn func() ifc.Validator
+	}{
+		{
+			name: "single pair",
+			pairs: []types.Pair{
+				{Key: "key", Value: "value"},
+			},
+			wantKeys:   []string{"key"},
+			wantValues: map[string]string{"key": "value"},
+		},
+		{
+			name: "multiple pairs preserve order",
+			pairs: []types.Pair{
+				{Key: "A", Value: "1"},
+				{Key: "B", Value: "2"},
+				{Key: "C", Value: "3"},
+			},
+			wantKeys:   []string{"A", "B", "C"},
+			wantValues: map[string]string{"A": "1", "B": "2", "C": "3"},
+		},
+		{
+			name: "multiple pairs out of order - loader order wins",
+			pairs: []types.Pair{
+				{Key: "third", Value: "3"},
+				{Key: "first", Value: "1"},
+				{Key: "second", Value: "2"},
+			},
+			wantKeys:   []string{"third", "first", "second"},
+			wantValues: map[string]string{"third": "3", "first": "1", "second": "2"},
+		},
+		{
+			name: "duplicate key returns error",
+			pairs: []types.Pair{
+				{Key: "dup", Value: "1"},
+				{Key: "dup", Value: "2"},
+			},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			loader := &fakeKvLoader{
+				Pairs: tt.pairs,
+				Val: func() ifc.Validator {
+					if tt.validatorFn != nil {
+						return tt.validatorFn()
+					}
+					return valtest_test.MakeFakeValidator()
+				}(),
+			}
+
+			args := types.ConfigMapArgs{
+				GeneratorArgs: types.GeneratorArgs{
+					Name: "envConfigMap",
+					KvPairSources: types.KvPairSources{
+						EnvSources: []string{"app.env"},
+					},
+				},
+			}
+
+			res, err := makeValidatedDataMap(loader, args.Name, args.KvPairSources)
+
+			if tt.wantErr {
+				require.Error(t, err)
+				return
+			}
+
+			require.NoError(t, err)
+			require.Exactly(t, tt.wantKeys, res.keys)
+			require.Exactly(t, tt.wantValues, res.values)
+		})
+	}
+}
+
+type fakeKvLoader struct {
+	Pairs []types.Pair
+	Val   ifc.Validator
+}
+
+func (f *fakeKvLoader) Load(_ types.KvPairSources) ([]types.Pair, error) {
+	return f.Pairs, nil
+}
+
+func (f *fakeKvLoader) Validator() ifc.Validator {
+	if f.Val != nil {
+		return f.Val
+	}
+	return valtest_test.MakeFakeValidator()
+}