diff --git a/CHANGELOG.md b/CHANGELOG.md
index db99c39eb30..5823aeea6cf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,9 @@ IMPROVEMENTS:
  * env: Default interpolation of optional meta fields of parameterized jobs to
    an empty string rather than the field key. [[GH-3720](https://github.com/hashicorp/nomad/issues/3720)]
 
+BUG FIXES:
+ * driver/docker: Fix docker credential helper support [[GH-3818](https://github.com/hashicorp/nomad/issues/3818)] [[GH-4221](https://github.com/hashicorp/nomad/issues/4221)]
+
 ## 0.8.3 (April 27, 2018)
 
 BUG FIXES:
diff --git a/client/driver/docker.go b/client/driver/docker.go
index cc31e547eae..d6a32601728 100644
--- a/client/driver/docker.go
+++ b/client/driver/docker.go
@@ -2130,13 +2130,15 @@ func authFromHelper(helperName string) authBackend {
 		helper := dockerAuthHelperPrefix + helperName
 		cmd := exec.Command(helper, "get")
 
-		// Ensure that the HTTPs prefix exists
-		if !strings.HasPrefix(repo, "https://") {
-			repo = fmt.Sprintf("https://%s", repo)
+		repoInfo, err := parseRepositoryInfo(repo)
+		if err != nil {
+			return nil, err
 		}
 
-		cmd.Stdin = strings.NewReader(repo)
+		// Ensure that the HTTPs prefix exists
+		repoAddr := fmt.Sprintf("https://%s", repoInfo.Hostname())
 
+		cmd.Stdin = strings.NewReader(repoAddr)
 		output, err := cmd.Output()
 		if err != nil {
 			switch err.(type) {