diff --git a/pkg/api/validation/validation.go b/pkg/api/validation/validation.go
index 3d4d906c571..47b48afc4ec 100644
--- a/pkg/api/validation/validation.go
+++ b/pkg/api/validation/validation.go
@@ -1107,6 +1107,7 @@ func validateSecretKeySelector(s *api.SecretKeySelector, fldPath *field.Path) fi
 
 func validateVolumeMounts(mounts []api.VolumeMount, volumes sets.String, fldPath *field.Path) field.ErrorList {
 	allErrs := field.ErrorList{}
+	mountpoints := sets.NewString()
 
 	for i, mnt := range mounts {
 		idxPath := fldPath.Index(i)
@@ -1120,6 +1121,10 @@ func validateVolumeMounts(mounts []api.VolumeMount, volumes sets.String, fldPath
 		} else if strings.Contains(mnt.MountPath, ":") {
 			allErrs = append(allErrs, field.Invalid(idxPath.Child("mountPath"), mnt.MountPath, "must not contain ':'"))
 		}
+		if mountpoints.Has(mnt.MountPath) {
+			allErrs = append(allErrs, field.Invalid(idxPath.Child("mountPath"), mnt.MountPath, "must be unique"))
+		}
+		mountpoints.Insert(mnt.MountPath)
 	}
 	return allErrs
 }
diff --git a/pkg/api/validation/validation_test.go b/pkg/api/validation/validation_test.go
index ad10d7917cf..701e3bd2706 100644
--- a/pkg/api/validation/validation_test.go
+++ b/pkg/api/validation/validation_test.go
@@ -1124,18 +1124,19 @@ func TestValidateVolumeMounts(t *testing.T) {
 
 	successCase := []api.VolumeMount{
 		{Name: "abc", MountPath: "/foo"},
-		{Name: "123", MountPath: "/foo"},
-		{Name: "abc-123", MountPath: "/bar"},
+		{Name: "123", MountPath: "/bar"},
+		{Name: "abc-123", MountPath: "/baz"},
 	}
 	if errs := validateVolumeMounts(successCase, volumes, field.NewPath("field")); len(errs) != 0 {
 		t.Errorf("expected success: %v", errs)
 	}
 
 	errorCases := map[string][]api.VolumeMount{
-		"empty name":      {{Name: "", MountPath: "/foo"}},
-		"name not found":  {{Name: "", MountPath: "/foo"}},
-		"empty mountpath": {{Name: "abc", MountPath: ""}},
-		"colon mountpath": {{Name: "abc", MountPath: "foo:bar"}},
+		"empty name":          {{Name: "", MountPath: "/foo"}},
+		"name not found":      {{Name: "", MountPath: "/foo"}},
+		"empty mountpath":     {{Name: "abc", MountPath: ""}},
+		"colon mountpath":     {{Name: "abc", MountPath: "foo:bar"}},
+		"mountpath collision": {{Name: "foo", MountPath: "/path/a"}, {Name: "bar", MountPath: "/path/a"}},
 	}
 	for k, v := range errorCases {
 		if errs := validateVolumeMounts(v, volumes, field.NewPath("field")); len(errs) == 0 {