diff --git a/go.mod b/go.mod
index 4a3715aed..9ca677e47 100644
--- a/go.mod
+++ b/go.mod
@@ -6,6 +6,7 @@ require (
 	github.com/hashicorp/terraform v0.12.3
 	github.com/mitchellh/gox v1.0.1
 	github.com/spf13/afero v1.2.2 // indirect
+	github.com/spf13/cast v1.3.1
 )
 
 go 1.13
diff --git a/go.sum b/go.sum
index b37df1a53..c657afb6f 100644
--- a/go.sum
+++ b/go.sum
@@ -536,6 +536,8 @@ github.com/spf13/cobra v0.0.5 h1:f0B+LkLX6DtmRH1isoNA9VTtNUK9K8xYd28JNNfOv/s=
 github.com/spf13/cobra v0.0.5/go.mod h1:3K3wKZymM7VvHMDS9+Akkh4K60UwM26emMESw8tLCHU=
 github.com/spf13/jwalterweatherman v1.0.0 h1:XHEdyB+EcvlqZamSM4ZOMGlc93t6AcsBEu9Gc1vn7yk=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
+github.com/spf13/cast v1.3.1 h1:nFm6S0SMdyzrzcmThSipiEubIDy8WEXKNZ0UOgiRpng=
+github.com/spf13/cast v1.3.1/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
 github.com/spf13/pflag v1.0.2/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
diff --git a/vendor/github.com/spf13/cast/.travis.yml b/vendor/github.com/spf13/cast/.travis.yml
index 6420d1c27..833a48799 100644
--- a/vendor/github.com/spf13/cast/.travis.yml
+++ b/vendor/github.com/spf13/cast/.travis.yml
@@ -4,6 +4,7 @@ env:
 sudo: required
 go:
   - "1.11.x"
+  - "1.12.x"
   - tip
 os:
   - linux
diff --git a/vendor/github.com/spf13/cast/Makefile b/vendor/github.com/spf13/cast/Makefile
index 7ccf8930b..f01a5dbb6 100644
--- a/vendor/github.com/spf13/cast/Makefile
+++ b/vendor/github.com/spf13/cast/Makefile
@@ -1,4 +1,4 @@
-# A Self-Documenting Makefile: http://marmelab.com/blog/2016/02/29/auto-documented-makefile.html
+GOVERSION := $(shell go version | cut -d ' ' -f 3 | cut -d '.' -f 2)
 
 .PHONY: check fmt lint test test-race vet test-cover-html help
 .DEFAULT_GOAL := help
@@ -12,11 +12,13 @@ test-race: ## Run tests with race detector
 	go test -race ./...
 
 fmt: ## Run gofmt linter
+ifeq "$(GOVERSION)" "12"
 	@for d in `go list` ; do \
 		if [ "`gofmt -l -s $$GOPATH/src/$$d | tee /dev/stderr`" ]; then \
 			echo "^ improperly formatted go files" && echo && exit 1; \
 		fi \
 	done
+endif
 
 lint: ## Run golint linter
 	@for d in `go list` ; do \
diff --git a/vendor/github.com/spf13/cast/caste.go b/vendor/github.com/spf13/cast/caste.go
index 75ef32c8d..70c7291be 100644
--- a/vendor/github.com/spf13/cast/caste.go
+++ b/vendor/github.com/spf13/cast/caste.go
@@ -819,15 +819,15 @@ func ToStringE(i interface{}) (string, error) {
 	case int8:
 		return strconv.FormatInt(int64(s), 10), nil
 	case uint:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case uint64:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case uint32:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case uint16:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case uint8:
-		return strconv.FormatInt(int64(s), 10), nil
+		return strconv.FormatUint(uint64(s), 10), nil
 	case []byte:
 		return string(s), nil
 	case template.HTML:
@@ -1131,19 +1131,14 @@ func ToStringSliceE(i interface{}) ([]string, error) {
 		return v, nil
 	case string:
 		return strings.Fields(v), nil
-	case []error:
-		for _, err := range i.([]error) {
-			a = append(a, err.Error())
-		}
-		return a, nil
 	case interface{}:
 		str, err := ToStringE(v)
 		if err != nil {
-			return a, fmt.Errorf("unable to cast %#v of type %T to []stringggg", i, i)
+			return a, fmt.Errorf("unable to cast %#v of type %T to []string", i, i)
 		}
 		return []string{str}, nil
 	default:
-		return a, fmt.Errorf("unable to cast %#v of type %T to []stringgg", i, i)
+		return a, fmt.Errorf("unable to cast %#v of type %T to []string", i, i)
 	}
 }
 
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 6c86f7728..3066fa154 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -368,7 +368,7 @@ github.com/sourcegraph/go-diff/diff
 # github.com/spf13/afero v1.2.2
 github.com/spf13/afero
 github.com/spf13/afero/mem
-# github.com/spf13/cast v1.3.0
+# github.com/spf13/cast v1.3.1
 github.com/spf13/cast
 # github.com/spf13/cobra v0.0.5
 github.com/spf13/cobra