diff --git a/go.mod b/go.mod
index 808064fb88..e0a3ae2aa8 100644
--- a/go.mod
+++ b/go.mod
@@ -1,7 +1,7 @@
 module github.com/awslabs/goformation/v4
 
 require (
-	github.com/imdario/mergo v0.3.11
+	github.com/imdario/mergo v0.3.12
 	github.com/onsi/ginkgo v1.14.2
 	github.com/onsi/gomega v1.10.3
 	github.com/sanathkr/go-yaml v0.0.0-20170819195128-ed9d249f429b
diff --git a/go.sum b/go.sum
index 10bb7d340b..bb639be231 100644
--- a/go.sum
+++ b/go.sum
@@ -16,8 +16,8 @@ github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMyw
 github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
-github.com/imdario/mergo v0.3.11 h1:3tnifQM4i+fbajXKBHXWEH+KvNHqojZ778UH75j3bGA=
-github.com/imdario/mergo v0.3.11/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
+github.com/imdario/mergo v0.3.12 h1:b6R2BslTbIEToALKP7LxUvijTsNI9TAe80pLWN2g/HU=
+github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
 github.com/nxadm/tail v1.4.4 h1:DQuhQpB1tVlglWS2hLQ5OV6B5r8aGxSrPc5Qo6uTN78=
 github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
diff --git a/vendor/github.com/imdario/mergo/.travis.yml b/vendor/github.com/imdario/mergo/.travis.yml
index dad29725f8..d324c43ba4 100644
--- a/vendor/github.com/imdario/mergo/.travis.yml
+++ b/vendor/github.com/imdario/mergo/.travis.yml
@@ -1,4 +1,7 @@
 language: go
+arch:
+    - amd64
+    - ppc64le
 install:
   - go get -t
   - go get golang.org/x/tools/cmd/cover
diff --git a/vendor/github.com/imdario/mergo/README.md b/vendor/github.com/imdario/mergo/README.md
index 876abb500a..aa8cbd7ce6 100644
--- a/vendor/github.com/imdario/mergo/README.md
+++ b/vendor/github.com/imdario/mergo/README.md
@@ -97,7 +97,7 @@ If Mergo is useful to you, consider buying me a coffee, a beer, or making a mont
 - [mantasmatelis/whooplist-server](https://github.com/mantasmatelis/whooplist-server)
 - [jnuthong/item_search](https://github.com/jnuthong/item_search)
 - [bukalapak/snowboard](https://github.com/bukalapak/snowboard)
-- [janoszen/containerssh](https://github.com/janoszen/containerssh)
+- [containerssh/containerssh](https://github.com/containerssh/containerssh)
 
 ## Install
 
diff --git a/vendor/github.com/imdario/mergo/merge.go b/vendor/github.com/imdario/mergo/merge.go
index afa84a1e29..8c2a8fcd90 100644
--- a/vendor/github.com/imdario/mergo/merge.go
+++ b/vendor/github.com/imdario/mergo/merge.go
@@ -95,13 +95,18 @@ func deepMerge(dst, src reflect.Value, visited map[uintptr]*visit, depth int, co
 				}
 			}
 		} else {
-			if (isReflectNil(dst) || overwrite) && (!isEmptyValue(src) || overwriteWithEmptySrc) {
+			if dst.CanSet() && (isReflectNil(dst) || overwrite) && (!isEmptyValue(src) || overwriteWithEmptySrc) {
 				dst.Set(src)
 			}
 		}
 	case reflect.Map:
 		if dst.IsNil() && !src.IsNil() {
-			dst.Set(reflect.MakeMap(dst.Type()))
+			if dst.CanSet() {
+				dst.Set(reflect.MakeMap(dst.Type()))
+			} else {
+				dst = src
+				return
+			}
 		}
 
 		if src.Kind() != reflect.Map {
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 50693d871d..5a39002a10 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -1,6 +1,6 @@
 # github.com/fsnotify/fsnotify v1.4.9
 github.com/fsnotify/fsnotify
-# github.com/imdario/mergo v0.3.11
+# github.com/imdario/mergo v0.3.12
 github.com/imdario/mergo
 # github.com/nxadm/tail v1.4.4
 github.com/nxadm/tail