diff --git a/pkg/chart/loader/load.go b/pkg/chart/loader/load.go
index 7cc8878a8..de4e95040 100644
--- a/pkg/chart/loader/load.go
+++ b/pkg/chart/loader/load.go
@@ -81,7 +81,7 @@ func LoadFiles(files []*BufferedFile) (*chart.Chart, error) {
 			if c.Metadata == nil {
 				c.Metadata = new(chart.Metadata)
 			}
-			if err := yaml.Unmarshal(f.Data, c.Metadata); err != nil {
+			if err := yaml.UnmarshalStrict(f.Data, c.Metadata); err != nil {
 				return c, errors.Wrap(err, "cannot load Chart.yaml")
 			}
 			// NOTE(bacongobbler): while the chart specification says that APIVersion must be set,
@@ -99,12 +99,12 @@ func LoadFiles(files []*BufferedFile) (*chart.Chart, error) {
 			continue
 		case f.Name == "Chart.lock":
 			c.Lock = new(chart.Lock)
-			if err := yaml.Unmarshal(f.Data, &c.Lock); err != nil {
+			if err := yaml.UnmarshalStrict(f.Data, &c.Lock); err != nil {
 				return c, errors.Wrap(err, "cannot load Chart.lock")
 			}
 		case f.Name == "values.yaml":
 			c.Values = make(map[string]interface{})
-			if err := yaml.Unmarshal(f.Data, &c.Values); err != nil {
+			if err := yaml.UnmarshalStrict(f.Data, &c.Values); err != nil {
 				return c, errors.Wrap(err, "cannot load values.yaml")
 			}
 		case f.Name == "values.schema.json":
@@ -119,7 +119,7 @@ func LoadFiles(files []*BufferedFile) (*chart.Chart, error) {
 			if c.Metadata.APIVersion != chart.APIVersionV1 {
 				log.Printf("Warning: Dependencies are handled in Chart.yaml since apiVersion \"v2\". We recommend migrating dependencies to Chart.yaml.")
 			}
-			if err := yaml.Unmarshal(f.Data, c.Metadata); err != nil {
+			if err := yaml.UnmarshalStrict(f.Data, c.Metadata); err != nil {
 				return c, errors.Wrap(err, "cannot load requirements.yaml")
 			}
 			if c.Metadata.APIVersion == chart.APIVersionV1 {
@@ -128,7 +128,7 @@ func LoadFiles(files []*BufferedFile) (*chart.Chart, error) {
 		// Deprecated: requirements.lock is deprecated use Chart.lock.
 		case f.Name == "requirements.lock":
 			c.Lock = new(chart.Lock)
-			if err := yaml.Unmarshal(f.Data, &c.Lock); err != nil {
+			if err := yaml.UnmarshalStrict(f.Data, &c.Lock); err != nil {
 				return c, errors.Wrap(err, "cannot load requirements.lock")
 			}
 			if c.Metadata == nil {
diff --git a/pkg/chart/loader/load_test.go b/pkg/chart/loader/load_test.go
index a737098b4..27f25644f 100644
--- a/pkg/chart/loader/load_test.go
+++ b/pkg/chart/loader/load_test.go
@@ -489,6 +489,17 @@ func TestLoadInvalidArchive(t *testing.T) {
 	}
 }
 
+func TestLoadWithDuplicateKeysInValuesFile(t *testing.T) {
+	l, err := Loader("testdata/frobnitz_with_duplicate_keys")
+	if err != nil {
+		t.Fatalf("Failed to load testdata: %s", err)
+	}
+
+	if _, err = l.Load(); err == nil {
+		t.Errorf("packages with a value yaml file with duplicate keys should not load")
+	}
+}
+
 func verifyChart(t *testing.T, c *chart.Chart) {
 	t.Helper()
 	if c.Name() == "" {
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/.helmignore b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/.helmignore
new file mode 100644
index 000000000..9973a57b8
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/.helmignore
@@ -0,0 +1 @@
+ignore/
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/Chart.lock b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/Chart.lock
new file mode 100644
index 000000000..6fcc2ed9f
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/Chart.lock
@@ -0,0 +1,8 @@
+dependencies:
+  - name: alpine
+    version: "0.1.0"
+    repository: https://example.com/charts
+  - name: mariner
+    version: "4.3.2"
+    repository: https://example.com/charts
+digest: invalid
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/Chart.yaml b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/Chart.yaml
new file mode 100644
index 000000000..fcd4a4a37
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/Chart.yaml
@@ -0,0 +1,27 @@
+apiVersion: v1
+name: frobnitz
+description: This is a frobnitz.
+version: "1.2.3"
+keywords:
+  - frobnitz
+  - sprocket
+  - dodad
+maintainers:
+  - name: The Helm Team
+    email: helm@example.com
+  - name: Someone Else
+    email: nobody@example.com
+sources:
+  - https://example.com/foo/bar
+home: http://example.com
+icon: https://example.com/64x64.png
+annotations:
+  extrakey: extravalue
+  anotherkey: anothervalue
+dependencies:
+  - name: alpine
+    version: "0.1.0"
+    repository: https://example.com/charts
+  - name: mariner
+    version: "4.3.2"
+    repository: https://example.com/charts
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/INSTALL.txt b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/INSTALL.txt
new file mode 100644
index 000000000..2010438c2
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/INSTALL.txt
@@ -0,0 +1 @@
+This is an install document. The client may display this.
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/LICENSE b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/LICENSE
new file mode 100644
index 000000000..6121943b1
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/LICENSE
@@ -0,0 +1 @@
+LICENSE placeholder.
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/README.md b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/README.md
new file mode 100644
index 000000000..8cf4cc3d7
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/README.md
@@ -0,0 +1,11 @@
+# Frobnitz
+
+This is an example chart.
+
+## Usage
+
+This is an example. It has no usage.
+
+## Development
+
+For developer info, see the top-level repository.
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/_ignore_me b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/_ignore_me
new file mode 100644
index 000000000..2cecca682
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/_ignore_me
@@ -0,0 +1 @@
+This should be ignored by the loader, but may be included in a chart.
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/Chart.yaml b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/Chart.yaml
new file mode 100644
index 000000000..79e0d65db
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/Chart.yaml
@@ -0,0 +1,5 @@
+apiVersion: v1
+name: alpine
+description: Deploy a basic Alpine Linux pod
+version: 0.1.0
+home: https://helm.sh/helm
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/README.md b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/README.md
new file mode 100644
index 000000000..b30b949dd
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/README.md
@@ -0,0 +1,9 @@
+This example was generated using the command `helm create alpine`.
+
+The `templates/` directory contains a very simple pod resource with a
+couple of parameters.
+
+The `values.toml` file contains the default values for the
+`alpine-pod.yaml` template.
+
+You can install this example using `helm install ./alpine`.
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast1/Chart.yaml b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast1/Chart.yaml
new file mode 100644
index 000000000..1c9dd5fa4
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast1/Chart.yaml
@@ -0,0 +1,5 @@
+apiVersion: v1
+name: mast1
+description: A Helm chart for Kubernetes
+version: 0.1.0
+home: ""
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast1/values.yaml b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast1/values.yaml
new file mode 100644
index 000000000..42c39c262
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast1/values.yaml
@@ -0,0 +1,4 @@
+# Default values for mast1.
+# This is a YAML-formatted file.
+# Declare name/value pairs to be passed into your templates.
+# name = "value"
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast2-0.1.0.tgz b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast2-0.1.0.tgz
new file mode 100644
index 000000000..61cb62051
Binary files /dev/null and b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/charts/mast2-0.1.0.tgz differ
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/templates/alpine-pod.yaml b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/templates/alpine-pod.yaml
new file mode 100644
index 000000000..21ae20aad
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/templates/alpine-pod.yaml
@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Pod
+metadata:
+  name: {{.Release.Name}}-{{.Chart.Name}}
+  labels:
+    app.kubernetes.io/managed-by: {{.Release.Service}}
+    app.kubernetes.io/name: {{.Chart.Name}}
+    helm.sh/chart: "{{.Chart.Name}}-{{.Chart.Version}}"
+spec:
+  restartPolicy: {{default "Never" .restart_policy}}
+  containers:
+  - name: waiter
+    image: "alpine:3.9"
+    command: ["/bin/sleep","9000"]
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/values.yaml b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/values.yaml
new file mode 100644
index 000000000..6c2aab7ba
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/alpine/values.yaml
@@ -0,0 +1,2 @@
+# The pod name
+name: "my-alpine"
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/mariner-4.3.2.tgz b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/mariner-4.3.2.tgz
new file mode 100644
index 000000000..3190136b0
Binary files /dev/null and b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/charts/mariner-4.3.2.tgz differ
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/docs/README.md b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/docs/README.md
new file mode 100644
index 000000000..d40747caf
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/docs/README.md
@@ -0,0 +1 @@
+This is a placeholder for documentation.
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/icon.svg b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/icon.svg
new file mode 100644
index 000000000..892130606
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/icon.svg
@@ -0,0 +1,8 @@
+<?xml version="1.0"?>
+<svg xmlns:svg="http://www.w3.org/2000/svg" xmlns="http://www.w3.org/2000/svg"
+    xmlns:xlink="http://www.w3.org/1999/xlink"
+    version="1.0" width="256" height="256" id="test">
+  <desc>Example icon</desc>
+  <rect id="first" x="2" y="2" width="40" height="60" fill="navy"/>
+  <rect id="second" x="15" y="4" width="40" height="60" fill="red"/>
+</svg>
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/ignore/me.txt b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/ignore/me.txt
new file mode 100644
index 000000000..e69de29bb
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/templates/template.tpl b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/templates/template.tpl
new file mode 100644
index 000000000..c651ee6a0
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/templates/template.tpl
@@ -0,0 +1 @@
+Hello {{.Name | default "world"}}
diff --git a/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/values.yaml b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/values.yaml
new file mode 100644
index 000000000..8f4a081f3
--- /dev/null
+++ b/pkg/chart/loader/testdata/frobnitz_with_duplicate_keys/values.yaml
@@ -0,0 +1,9 @@
+# A values file contains configuration.
+
+name: "Some Name"
+
+section:
+  name: "Name in a section"
+
+section:
+  name: "Duplicate section name"