diff --git a/sdk/helper/useragent/useragent.go b/sdk/helper/useragent/useragent.go
index 9bc212535..e7e23ac2b 100644
--- a/sdk/helper/useragent/useragent.go
+++ b/sdk/helper/useragent/useragent.go
@@ -44,12 +44,29 @@ func String(comments ...string) string {
 // Given comments will be appended to the semicolon-delimited comment section.
 //
 // e.g. Vault/0.10.4 (+https://www.vaultproject.io/; azure-auth; go1.10.1; comment-0; comment-1)
+//
+// Returns an empty string if the given env is nil.
 func PluginString(env *logical.PluginEnvironment, pluginName string, comments ...string) string {
+	if env == nil {
+		return ""
+	}
+
+	// Construct comments
 	c := []string{"+" + projectURL}
 	if pluginName != "" {
 		c = append(c, pluginName)
 	}
 	c = append(c, rt)
 	c = append(c, comments...)
-	return fmt.Sprintf("Vault/%s (%s)", env.VaultVersion, strings.Join(c, "; "))
+
+	// Construct version string
+	v := env.VaultVersion
+	if env.VaultVersionPrerelease != "" {
+		v = fmt.Sprintf("%s-%s", v, env.VaultVersionPrerelease)
+	}
+	if env.VaultVersionMetadata != "" {
+		v = fmt.Sprintf("%s+%s", v, env.VaultVersionMetadata)
+	}
+
+	return fmt.Sprintf("Vault/%s (%s)", v, strings.Join(c, "; "))
 }
diff --git a/sdk/helper/useragent/useragent_test.go b/sdk/helper/useragent/useragent_test.go
index bfd439603..f0d014f6c 100644
--- a/sdk/helper/useragent/useragent_test.go
+++ b/sdk/helper/useragent/useragent_test.go
@@ -51,12 +51,10 @@ func TestUserAgent(t *testing.T) {
 func TestUserAgentPlugin(t *testing.T) {
 	projectURL = "https://vault-test.com"
 	rt = "go5.0"
-	env := &logical.PluginEnvironment{
-		VaultVersion: "1.2.3",
-	}
 
 	type args struct {
 		pluginName string
+		pluginEnv  *logical.PluginEnvironment
 		comments   []string
 	}
 	tests := []struct {
@@ -64,15 +62,38 @@ func TestUserAgentPlugin(t *testing.T) {
 		args args
 		want string
 	}{
+		{
+			name: "Plugin user agent with nil plugin env",
+			args: args{
+				pluginEnv: nil,
+			},
+			want: "",
+		},
 		{
 			name: "Plugin user agent without plugin name",
-			args: args{},
+			args: args{
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion: "1.2.3",
+				},
+			},
+			want: "Vault/1.2.3 (+https://vault-test.com; go5.0)",
+		},
+		{
+			name: "Plugin user agent without plugin name",
+			args: args{
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion: "1.2.3",
+				},
+			},
 			want: "Vault/1.2.3 (+https://vault-test.com; go5.0)",
 		},
 		{
 			name: "Plugin user agent with plugin name",
 			args: args{
 				pluginName: "azure-auth",
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion: "1.2.3",
+				},
 			},
 			want: "Vault/1.2.3 (+https://vault-test.com; azure-auth; go5.0)",
 		},
@@ -80,7 +101,10 @@ func TestUserAgentPlugin(t *testing.T) {
 			name: "Plugin user agent with plugin name and additional comment",
 			args: args{
 				pluginName: "azure-auth",
-				comments:   []string{"pid-abcdefg"},
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion: "1.2.3",
+				},
+				comments: []string{"pid-abcdefg"},
 			},
 			want: "Vault/1.2.3 (+https://vault-test.com; azure-auth; go5.0; pid-abcdefg)",
 		},
@@ -88,21 +112,64 @@ func TestUserAgentPlugin(t *testing.T) {
 			name: "Plugin user agent with plugin name and additional comments",
 			args: args{
 				pluginName: "azure-auth",
-				comments:   []string{"pid-abcdefg", "cloud-provider"},
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion: "1.2.3",
+				},
+				comments: []string{"pid-abcdefg", "cloud-provider"},
 			},
 			want: "Vault/1.2.3 (+https://vault-test.com; azure-auth; go5.0; pid-abcdefg; cloud-provider)",
 		},
 		{
 			name: "Plugin user agent with no plugin name and additional comments",
 			args: args{
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion: "1.2.3",
+				},
 				comments: []string{"pid-abcdefg", "cloud-provider"},
 			},
 			want: "Vault/1.2.3 (+https://vault-test.com; go5.0; pid-abcdefg; cloud-provider)",
 		},
+		{
+			name: "Plugin user agent with version prerelease",
+			args: args{
+				pluginName: "azure-auth",
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion:           "1.2.3",
+					VaultVersionPrerelease: "dev",
+				},
+				comments: []string{"pid-abcdefg", "cloud-provider"},
+			},
+			want: "Vault/1.2.3-dev (+https://vault-test.com; azure-auth; go5.0; pid-abcdefg; cloud-provider)",
+		},
+		{
+			name: "Plugin user agent with version metadata",
+			args: args{
+				pluginName: "azure-auth",
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion:         "1.2.3",
+					VaultVersionMetadata: "ent",
+				},
+				comments: []string{"pid-abcdefg", "cloud-provider"},
+			},
+			want: "Vault/1.2.3+ent (+https://vault-test.com; azure-auth; go5.0; pid-abcdefg; cloud-provider)",
+		},
+		{
+			name: "Plugin user agent with version prerelease and metadata",
+			args: args{
+				pluginName: "azure-auth",
+				pluginEnv: &logical.PluginEnvironment{
+					VaultVersion:           "1.2.3",
+					VaultVersionPrerelease: "dev",
+					VaultVersionMetadata:   "ent",
+				},
+				comments: []string{"pid-abcdefg", "cloud-provider"},
+			},
+			want: "Vault/1.2.3-dev+ent (+https://vault-test.com; azure-auth; go5.0; pid-abcdefg; cloud-provider)",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if got := PluginString(env, tt.args.pluginName, tt.args.comments...); got != tt.want {
+			if got := PluginString(tt.args.pluginEnv, tt.args.pluginName, tt.args.comments...); got != tt.want {
 				t.Errorf("PluginString() = %v, want %v", got, tt.want)
 			}
 		})