diff --git a/dump_postgres.go b/dump_postgres.go
index a1cf431..bb26fd9 100644
--- a/dump_postgres.go
+++ b/dump_postgres.go
@@ -15,8 +15,7 @@ func NewPostgresDumper(container *types.ContainerJSON) *PostgresDumper {
 	}
 }
 
-func (d *PostgresDumper) Dump() error {
-	fmt.Printf("Dumping postgres database from container %s...\n", d.Container.Name)
+func (d *PostgresDumper) buildConnStr() string {
 	env := parseEnv(d.Container.Config.Env)
 
 	user := "root"
@@ -24,7 +23,7 @@ func (d *PostgresDumper) Dump() error {
 		user = u
 	}
 
-	db := ""
+	db := "postgres"
 	if d, has := env["POSTGRES_DB"]; has {
 		db = d
 	}
@@ -41,9 +40,13 @@ func (d *PostgresDumper) Dump() error {
 
 	host := d.Container.NetworkSettings.DefaultNetworkSettings.IPAddress
 
-	connStr := fmt.Sprintf("postgresql://%s:%s@%s:%s/%s", user, pw, host, port, db)
+	return fmt.Sprintf("postgresql://%s:%s@%s:%s/%s", user, pw, host, port, db)
+}
 
-	// TODO: Check postgres image version and use the correct pg_dump --> Test!
+func (d *PostgresDumper) Dump() error {
+	fmt.Printf("Dumping postgres database from container %s...\n", d.Container.Name)
+
+	connStr := d.buildConnStr()
 
 	return runAndSaveCommand(getDumpFilename(d.Container.Name), "pg_dump", "--dbname", connStr)
 }
diff --git a/dump_postgres_test.go b/dump_postgres_test.go
new file mode 100644
index 0000000..8e31a7f
--- /dev/null
+++ b/dump_postgres_test.go
@@ -0,0 +1,117 @@
+package main
+
+import (
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/api/types/container"
+	"testing"
+)
+
+func TestPostgresDumper_buildConnStr(t *testing.T) {
+	nw := &types.NetworkSettings{
+		DefaultNetworkSettings: types.DefaultNetworkSettings{
+			IPAddress: "1.2.3.4",
+		},
+	}
+	tests := []struct {
+		name      string
+		container *types.ContainerJSON
+		want      string
+	}{
+		{
+			name: "values for everything",
+			container: &types.ContainerJSON{
+				NetworkSettings: nw,
+				Config: &container.Config{
+					Env: []string{
+						"POSTGRES_USER=loremipsum",
+						"POSTGRES_DB=ipsum",
+						"POSTGRES_PASSWORD=notapassword",
+						"POSTGRES_PORT=1234",
+					},
+				},
+			},
+			want: "postgresql://loremipsum:notapassword@1.2.3.4:1234/ipsum",
+		},
+		{
+			name: "no user",
+			container: &types.ContainerJSON{
+				NetworkSettings: nw,
+				Config: &container.Config{
+					Env: []string{
+						"POSTGRES_DB=ipsum",
+						"POSTGRES_PASSWORD=notapassword",
+						"POSTGRES_PORT=1234",
+					},
+				},
+			},
+			want: "postgresql://root:notapassword@1.2.3.4:1234/ipsum",
+		},
+		{
+			name: "no password",
+			container: &types.ContainerJSON{
+				NetworkSettings: nw,
+				Config: &container.Config{
+					Env: []string{
+						"POSTGRES_USER=loremipsum",
+						"POSTGRES_DB=ipsum",
+						"POSTGRES_PORT=1234",
+					},
+				},
+			},
+			want: "postgresql://loremipsum:@1.2.3.4:1234/ipsum",
+		},
+		{
+			name: "no password, but root",
+			container: &types.ContainerJSON{
+				NetworkSettings: nw,
+				Config: &container.Config{
+					Env: []string{
+						"POSTGRES_USER=loremipsum",
+						"POSTGRES_DB=ipsum",
+						"POSTGRES_PORT=1234",
+						"POSTGRES_ROOT_PASSWORD=roooot",
+					},
+				},
+			},
+			want: "postgresql://loremipsum:roooot@1.2.3.4:1234/ipsum",
+		},
+		{
+			name: "no port",
+			container: &types.ContainerJSON{
+				NetworkSettings: nw,
+				Config: &container.Config{
+					Env: []string{
+						"POSTGRES_USER=loremipsum",
+						"POSTGRES_DB=ipsum",
+						"POSTGRES_PASSWORD=notapassword",
+					},
+				},
+			},
+			want: "postgresql://loremipsum:notapassword@1.2.3.4:5432/ipsum",
+		},
+		{
+			name: "no db",
+			container: &types.ContainerJSON{
+				NetworkSettings: nw,
+				Config: &container.Config{
+					Env: []string{
+						"POSTGRES_USER=loremipsum",
+						"POSTGRES_PASSWORD=notapassword",
+						"POSTGRES_PORT=1234",
+					},
+				},
+			},
+			want: "postgresql://loremipsum:notapassword@1.2.3.4:1234/postgres",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			d := &PostgresDumper{
+				Container: tt.container,
+			}
+			if got := d.buildConnStr(); got != tt.want {
+				t.Errorf("buildConnStr() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}