diff --git a/cmd/coordinator/main.go b/cmd/coordinator/main.go
index fb4b2947..a6e8fdbf 100644
--- a/cmd/coordinator/main.go
+++ b/cmd/coordinator/main.go
@@ -14,11 +14,10 @@ func main() {
 	conf.ParseFlags()
 
 	log := logger.NewConsole(conf.Coordinator.Debug, "c", false)
-
 	log.Info().Msgf("version %s", Version)
-	log.Info().Msgf("conf version: %v", conf.Version)
+	log.Info().Msgf("conf: v%v", conf.Version)
 	if log.GetLevel() < logger.InfoLevel {
-		log.Debug().Msgf("config: %+v", conf)
+		log.Debug().Msgf("conf: %+v", conf)
 	}
 	c := coordinator.New(conf, log)
 	c.Start()
diff --git a/cmd/worker/main.go b/cmd/worker/main.go
index 5dc60ce5..a697b4f4 100644
--- a/cmd/worker/main.go
+++ b/cmd/worker/main.go
@@ -18,9 +18,9 @@ func run() {
 
 	log := logger.NewConsole(conf.Worker.Debug, "w", false)
 	log.Info().Msgf("version %s", Version)
-	log.Info().Msgf("conf version: %v", conf.Version)
+	log.Info().Msgf("conf: v%v", conf.Version)
 	if log.GetLevel() < logger.InfoLevel {
-		log.Debug().Msgf("config: %+v", conf)
+		log.Debug().Msgf("conf: %+v", conf)
 	}
 
 	done := os.ExpectTermination()
diff --git a/configs/config.yaml b/configs/config.yaml
index a0fe7051..cd8c2f1a 100644
--- a/configs/config.yaml
+++ b/configs/config.yaml
@@ -1,3 +1,4 @@
+LOL123L: yolo
 #
 # Application configuration file
 #
@@ -179,7 +180,8 @@ emulator:
       #       their tick rate (1/system FPS), but OpenGL cores like N64 may have significant
       #       frame rendering time inconsistencies. In general, VFR for CFR cores leads to
       #       noticeable video stutter (with the current frame rendering time calculations).
-      #   - options ([]string) a list of Libretro core options for tweaking
+      #   - options ([]string) a list of Libretro core options for tweaking.
+      #       All keys of the options should be in the double quotes in order to preserve upper-case symbols.
       list:
         gba:
           lib: mgba_libretro
@@ -191,8 +193,8 @@ emulator:
           folder: psx
           # see: https://github.com/libretro/pcsx_rearmed/blob/master/frontend/libretro_core_options.h
           options:
-            pcsx_rearmed_drc: enabled
-            pcsx_rearmed_display_internal_fps: disabled
+            "pcsx_rearmed_drc": enabled
+            "pcsx_rearmed_display_internal_fps": disabled
         # MAME core requires additional manual setup, please read:
         # https://docs.libretro.com/library/fbneo/
         mame:
@@ -213,21 +215,21 @@ emulator:
           vfr: true
           # see: https://github.com/libretro/mupen64plus-libretro-nx/blob/master/libretro/libretro_core_options.h
           options:
-            mupen64plus-169screensize: 640x360
-            mupen64plus-43screensize: 320x240
-            mupen64plus-EnableCopyColorToRDRAM: Off
-            mupen64plus-EnableCopyDepthToRDRAM: Off
-            mupen64plus-EnableEnhancedTextureStorage: True
-            mupen64plus-EnableFBEmulation: True
-            mupen64plus-EnableLegacyBlending: True
-            mupen64plus-FrameDuping: False
-            mupen64plus-MaxTxCacheSize: 8000
-            mupen64plus-ThreadedRenderer: False
-            mupen64plus-cpucore: dynamic_recompiler
-            mupen64plus-pak1: memory
-            mupen64plus-rdp-plugin: gliden64
-            mupen64plus-rsp-plugin: hle
-            mupen64plus-astick-sensitivity: 100
+            "mupen64plus-169screensize": 640x360
+            "mupen64plus-43screensize": 320x240
+            "mupen64plus-EnableCopyColorToRDRAM": Off
+            "mupen64plus-EnableCopyDepthToRDRAM": Off
+            "mupen64plus-EnableEnhancedTextureStorage": True
+            "mupen64plus-EnableFBEmulation": True
+            "mupen64plus-EnableLegacyBlending": True
+            "mupen64plus-FrameDuping": False
+            "mupen64plus-MaxTxCacheSize": 8000
+            "mupen64plus-ThreadedRenderer": False
+            "mupen64plus-cpucore": dynamic_recompiler
+            "mupen64plus-pak1": memory
+            "mupen64plus-rdp-plugin": gliden64
+            "mupen64plus-rsp-plugin": hle
+            "mupen64plus-astick-sensitivity": 100
 
 encoder:
   audio:
diff --git a/pkg/config/loader.go b/pkg/config/loader.go
index d75ddf0c..3ba6c3df 100644
--- a/pkg/config/loader.go
+++ b/pkg/config/loader.go
@@ -12,33 +12,72 @@ import (
 
 const EnvPrefix = "CLOUD_GAME_"
 
+type Kv = map[string]any
+type Bytes []byte
+
+func (b *Bytes) ReadBytes() ([]byte, error) { return *b, nil }
+func (b *Bytes) Read() (Kv, error)          { return nil, nil }
+
 type File string
 
-func (f *File) ReadBytes() ([]byte, error)            { return os.ReadFile(string(*f)) }
-func (f *File) Read() (map[string]interface{}, error) { return nil, nil }
+func (f *File) ReadBytes() ([]byte, error) { return os.ReadFile(string(*f)) }
+func (f *File) Read() (Kv, error)          { return nil, nil }
 
 type YAML struct{}
 
-func (p *YAML) Marshal(map[string]interface{}) ([]byte, error) { return nil, nil }
-func (p *YAML) Unmarshal(b []byte) (map[string]interface{}, error) {
-	var out map[string]interface{}
-	if err := yaml.Unmarshal(b, &out); err != nil {
+func (p *YAML) Marshal(Kv) ([]byte, error) { return nil, nil }
+func (p *YAML) Unmarshal(b []byte) (Kv, error) {
+	var out Kv
+	klw := keysToLower(b)
+	if err := yaml.Unmarshal(klw, &out); err != nil {
 		return nil, err
 	}
 	return out, nil
 }
 
+// keysToLower iterates YAML bytes and tries to lower the keys.
+// Used for merging with environment vars which are lowered as well.
+func keysToLower(in []byte) []byte {
+	l, r, ignore := 0, 0, false
+	for i, b := range in {
+		switch b {
+		case '#': // skip comments
+			ignore = true
+		case ':': // lower left chunk before the next : symbol
+			if ignore {
+				continue
+			}
+			r = i
+			ignore = true
+			for j := l; j <= r; j++ {
+				c := in[j]
+				// we skip the line with the first explicit " string symbol
+				if c == '"' {
+					break
+				}
+				if 'A' <= c && c <= 'Z' {
+					in[j] += 'a' - 'A'
+				}
+			}
+		case '\n':
+			l = i
+			ignore = false
+		}
+	}
+	return in
+}
+
 type Env string
 
 func (e *Env) ReadBytes() ([]byte, error) { return nil, nil }
-func (e *Env) Read() (map[string]interface{}, error) {
+func (e *Env) Read() (Kv, error) {
 	var keys []string
 	for _, k := range os.Environ() {
 		if strings.HasPrefix(k, string(*e)) {
 			keys = append(keys, k)
 		}
 	}
-	mp := make(map[string]interface{})
+	mp := make(Kv)
 	for _, k := range keys {
 		parts := strings.SplitN(k, "=", 2)
 		n := strings.ToLower(strings.TrimPrefix(parts[0], string(*e)))
@@ -65,10 +104,10 @@ var k = koanf.New("_")
 // LoadConfig loads a configuration file into the given struct.
 // The path param specifies a custom path to the configuration file.
 // Reads and puts environment variables with the prefix CLOUD_GAME_.
-func LoadConfig(config any, path string) error {
-	dirs := []string{path}
-	if path == "" {
-		dirs = append(dirs, ".", "configs", "../../../configs")
+func LoadConfig(config any, path string) (err error) {
+	dirs := []string{".", "configs", "../../../configs"}
+	if path != "" {
+		dirs = append([]string{path}, dirs...)
 	}
 
 	homeDir := ""
diff --git a/pkg/config/loader_test.go b/pkg/config/loader_test.go
index c0e7a116..b97fed5d 100644
--- a/pkg/config/loader_test.go
+++ b/pkg/config/loader_test.go
@@ -2,6 +2,7 @@ package config
 
 import (
 	"os"
+	"reflect"
 	"testing"
 )
 
@@ -30,3 +31,28 @@ func TestConfigEnv(t *testing.T) {
 		t.Errorf("%v is not x", v)
 	}
 }
+
+func Test_keysToLower(t *testing.T) {
+	type args struct {
+		in []byte
+	}
+	tests := []struct {
+		name string
+		args args
+		want []byte
+	}{
+		{name: "empty", args: args{in: []byte{}}, want: []byte{}},
+		{name: "case", args: args{
+			in: []byte("KEY:1\n#Comment with:\n      	KeY123_NamE: 1\n\n\n\nAAA:123\n  \"KeyKey\":2\n"),
+		},
+			want: []byte("key:1\n#Comment with:\n      	key123_name: 1\n\n\n\naaa:123\n  \"KeyKey\":2\n"),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := keysToLower(tt.args.in); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("keysToLower() = %v, want %v", string(got), string(tt.want))
+			}
+		})
+	}
+}