diff --git a/internal/gamefile.go b/internal/gamefile.go
index 999b45c..80e3a19 100644
--- a/internal/gamefile.go
+++ b/internal/gamefile.go
@@ -53,9 +53,9 @@ func normalizeGameID(id string) string {
 	}
 
 	prefix := strings.ToUpper(matches[1])
-	number := matches[2] + matches[3]
+	number := matches[2] + "." + matches[3]
 
-	return prefix + "-" + number
+	return prefix + "_" + number
 }
 
 func renameGameFile(filePath, gameName string) (string, error) {
diff --git a/internal/gamefile_test.go b/internal/gamefile_test.go
index 3f65c35..37cccad 100644
--- a/internal/gamefile_test.go
+++ b/internal/gamefile_test.go
@@ -12,37 +12,37 @@ func TestParseCases(t *testing.T) {
 		{
 			name:     "SLUS with underscore and dot",
 			content:  []byte("Some binary data\x00\x00SLUS_123.45\x00\x00more data"),
-			expected: "SLUS-12345",
+			expected: "SLUS_123.45",
 		},
 		{
 			name:     "SLUS with hyphen",
 			content:  []byte("\x00\x00\x00SLUS-12345\x00\x00\x00"),
-			expected: "SLUS-12345",
+			expected: "SLUS_123.45",
 		},
 		{
 			name:     "SLES format",
 			content:  []byte("Header data\x00SLES_987.65\x00footer"),
-			expected: "SLES-98765",
+			expected: "SLES_987.65",
 		},
 		{
 			name:     "SLPS format",
 			content:  []byte("\xFF\xFESLPS_456.78\x00"),
-			expected: "SLPS-45678",
+			expected: "SLPS_456.78",
 		},
 		{
 			name:     "SCUS format",
 			content:  []byte("SCUS-97512"),
-			expected: "SCUS-97512",
+			expected: "SCUS_975.12",
 		},
 		{
 			name:     "No separator format",
 			content:  []byte("\x00\x00SLUS12345\x00\x00"),
-			expected: "SLUS-12345",
+			expected: "SLUS_123.45",
 		},
 		{
 			name:     "With spaces",
 			content:  []byte("SLUS 123.45"),
-			expected: "SLUS-12345",
+			expected: "SLUS_123.45",
 		},
 		{
 			name:     "No game ID found",
@@ -82,31 +82,31 @@ func TestNormalize(t *testing.T) {
 	}{
 		{
 			input:    "SLUS-12345",
-			expected: "SLUS-12345",
+			expected: "SLUS_123.45",
 		},
 		{
 			input:    "SLES_987.65",
-			expected: "SLES-98765",
+			expected: "SLES_987.65",
 		},
 		{
 			input:    "SLPS_456.78",
-			expected: "SLPS-45678",
+			expected: "SLPS_456.78",
 		},
 		{
 			input:    "scus-97512",
-			expected: "SCUS-97512",
+			expected: "SCUS_975.12",
 		},
 		{
 			input:    "SLUS12345",
-			expected: "SLUS-12345",
+			expected: "SLUS_123.45",
 		},
 		{
 			input:    "SLUS123.45",
-			expected: "SLUS-12345",
+			expected: "SLUS_123.45",
 		},
 		{
 			input:    "SLUs123.45",
-			expected: "SLUS-12345",
+			expected: "SLUS_123.45",
 		},
 	}