diff --git a/utils/common/src/commonMain/kotlin/com/insanusmokrassar/postssystem/utils/common/KnownMimeTypes.kt b/utils/common/src/commonMain/kotlin/com/insanusmokrassar/postssystem/utils/common/KnownMimeTypes.kt
index 233dea2f..cedd2f51 100644
--- a/utils/common/src/commonMain/kotlin/com/insanusmokrassar/postssystem/utils/common/KnownMimeTypes.kt
+++ b/utils/common/src/commonMain/kotlin/com/insanusmokrassar/postssystem/utils/common/KnownMimeTypes.kt
@@ -8,8 +8,6 @@ interface MimeType {
 }
 data class CustomMimeType(override val raw: String) : MimeType
 
-private const val imageMainType = "image"
-
 sealed class KnownMimeTypes(override val raw: String) : MimeType {
     object Any : MimeType, KnownMimeTypes("*/*")
     sealed class Application(raw: String) : MimeType, KnownMimeTypes(raw) {
@@ -1437,6 +1435,10 @@ internal val knownMimeTypes: Set<MimeType> = setOf(
     KnownMimeTypes.XConference.XCooltalk,
 )
 
-fun findBuiltinMimeType(from: String): MimeType? {
-    return knownMimeTypes.firstOrNull { it.raw == from }
+val knownMimeTypesMap by lazy {
+    knownMimeTypes.associateBy { it.raw }
+}
+
+fun findBuiltinMimeType(from: String): MimeType? {
+    return knownMimeTypesMap[from]
 }