diff --git a/Dockerfile b/Dockerfile
index 8d1c23f..c03600f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,5 @@
 FROM golang:1.11
 
-RUN apt-get update && apt-get install -y --no-install-recommends mysql-client && rm -rf /var/lib/apt/lists/*
-
-RUN apt-get update && apt-get install -y postgresql-client
+RUN apt-get update && apt-get install -y --no-install-recommends mysql-client postgresql-client && rm -rf /var/lib/apt/lists/*
 
 ENTRYPOINT [ "go", "test", "-v", "." ]
diff --git a/README.md b/README.md
index 7108fe1..b45421f 100644
--- a/README.md
+++ b/README.md
@@ -64,8 +64,7 @@ sql all "SELECT * FROM users WHERE name = 'John'"
 
 ## Dependencies
 
-- mysql
-- psql
+- mysql-client and/or postgresql-client
 - ssh (only if you configure an "appServer")
 
 ## Contribute
diff --git a/config.go b/config.go
index 6ca017c..2b05f02 100644
--- a/config.go
+++ b/config.go
@@ -16,7 +16,6 @@ type database struct {
 	User      string
 	Pass      string
 	SQLType   string
-	_sqlType  sqlType
 }
 
 func mustReadDatabasesConfigFile() map[string]database {
@@ -68,17 +67,5 @@ func mustReadDatabasesConfigFile() map[string]database {
 		usage("Couldn't find any database configurations on .databases.json. Looked like this:\n\n%v\n", string(byts))
 	}
 
-	for dbName, db := range databases {
-		typeStr := db.SQLType
-		if typeStr == "" {
-			typeStr = "mysql"
-		}
-		if _, ok := validSQLTypes[typeStr]; !ok {
-			usage("Unknown sql type %v for %v", typeStr, dbName)
-		}
-		db._sqlType = validSQLTypes[typeStr]
-		databases[dbName] = db
-	}
-
 	return databases
 }
diff --git a/main.go b/main.go
index b74aa02..710be69 100644
--- a/main.go
+++ b/main.go
@@ -78,7 +78,12 @@ func _main(databases map[string]database, databasesArgs []string, query string,
 	sqlTypes := map[sqlType]exists{}
 	var sqlType sqlType
 	for _, db := range targetDatabases {
-		sqlType = databases[db]._sqlType
+		database := databases[db]
+		typ, ok := validSQLTypes[database.SQLType]
+		if !ok {
+			usage("Unknown sql type %v for %v", database.SQLType, db)
+		}
+		sqlType = typ
 		sqlTypes[sqlType] = exists{}
 		if len(sqlTypes) > 1 {
 			usage("More than one sql types specified in target databases.")
diff --git a/main_test.go b/main_test.go
index e3cfe19..b23ad29 100644
--- a/main_test.go
+++ b/main_test.go
@@ -28,9 +28,9 @@ func Test_MySQL(t *testing.T) {
 
 	var (
 		testConfig = map[string]database{
-			"db1": database{DbServer: "test-mysql", DbName: "db1", User: "root", Pass: "", _sqlType: mySQL},
-			"db2": database{DbServer: "test-mysql", DbName: "db2", User: "root", Pass: "", _sqlType: mySQL},
-			"db3": database{DbServer: "test-mysql", DbName: "db3", User: "root", Pass: "", _sqlType: mySQL},
+			"db1": database{DbServer: "test-mysql", DbName: "db1", User: "root", Pass: "", SQLType: "mysql"},
+			"db2": database{DbServer: "test-mysql", DbName: "db2", User: "root", Pass: "", SQLType: ""},
+			"db3": database{DbServer: "test-mysql", DbName: "db3", User: "root", Pass: "", SQLType: ""},
 		}
 		ts = []struct {
 			name      string
@@ -129,9 +129,9 @@ func Test_PostgreSQL(t *testing.T) {
 
 	var (
 		testConfig = map[string]database{
-			"db1": database{DbServer: "test-postgres", DbName: "db1", User: "root", Pass: "", _sqlType: postgreSQL},
-			"db2": database{DbServer: "test-postgres", DbName: "db2", User: "root", Pass: "", _sqlType: postgreSQL},
-			"db3": database{DbServer: "test-postgres", DbName: "db3", User: "root", Pass: "", _sqlType: postgreSQL},
+			"db1": database{DbServer: "test-postgres", DbName: "db1", User: "root", Pass: "", SQLType: "postgres"},
+			"db2": database{DbServer: "test-postgres", DbName: "db2", User: "root", Pass: "", SQLType: "postgres"},
+			"db3": database{DbServer: "test-postgres", DbName: "db3", User: "root", Pass: "", SQLType: "postgres"},
 		}
 		ts = []struct {
 			name      string
diff --git a/sql_runner.go b/sql_runner.go
index df3e52c..a43c5b9 100644
--- a/sql_runner.go
+++ b/sql_runner.go
@@ -29,6 +29,7 @@ type sqlOptions struct {
 }
 
 var validSQLTypes = map[string]sqlType{
+	"":         mySQL,
 	"mysql":    mySQL,
 	"postgres": postgreSQL,
 }