diff --git a/CHANGELOG.md b/CHANGELOG.md
index 279fada196b63f66fccc81596f2c8937436d5110..08005425972bcbe4001a4c0022acccd6289d503c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 ###Changelog
 
+####Version 1.6.3
+* bug fixes
+
 ####Version 1.6.2
 * fixed issues with connection time out when server does not support ping
 
diff --git a/build.gradle b/build.gradle
index c5fb8381ed0410a7f95e585874d5b92c8ad90514..a434faabc2ef5d964649ab1fe1889f89d7072dcf 100644
--- a/build.gradle
+++ b/build.gradle
@@ -48,7 +48,7 @@ android {
 	defaultConfig {
 		minSdkVersion 14
 		targetSdkVersion 21
-		versionCode 86
+		versionCode 87
 		versionName "1.7.0-alpha"
 	}
 
diff --git a/src/main/java/eu/siacs/conversations/utils/MimeUtils.java b/src/main/java/eu/siacs/conversations/utils/MimeUtils.java
index a9e89d1b716ce67866d012fa459fc8a40fbc0c65..d45444240732d9445e4899a17d7c4431366a583a 100644
--- a/src/main/java/eu/siacs/conversations/utils/MimeUtils.java
+++ b/src/main/java/eu/siacs/conversations/utils/MimeUtils.java
@@ -458,7 +458,7 @@ public final class MimeUtils {
         if (extension == null || extension.isEmpty()) {
             return null;
         }
-        return extensionToMimeTypeMap.get(extension);
+        return extensionToMimeTypeMap.get(extension.toLowerCase());
     }
     /**
      * Returns true if the given extension has a registered MIME type.