diff --git a/src/main/java/lc/FontFunCaptcha.java b/src/main/java/lc/FontFunCaptcha.java
index 3603b23..ce55c04 100644
--- a/src/main/java/lc/FontFunCaptcha.java
+++ b/src/main/java/lc/FontFunCaptcha.java
@@ -66,7 +66,7 @@ public class FontFunCaptcha implements ChallengeProvider{
     public Challenge returnChallenge() {
         String secret = HelperFunctions.randomString(7);
         String path = "./lib/fonts/";
-        return new Challenge(fontFun(secret,"medium",path),"png",secret.toLowerCase());
+        return new Challenge(fontFun(secret,"medium",path),"image/png",secret.toLowerCase());
     }
 
     public boolean checkAnswer(String secret, String answer){
diff --git a/src/main/java/lc/GifCaptcha.java b/src/main/java/lc/GifCaptcha.java
index 750438c..852b0c9 100644
--- a/src/main/java/lc/GifCaptcha.java
+++ b/src/main/java/lc/GifCaptcha.java
@@ -42,7 +42,7 @@ public class GifCaptcha implements ChallengeProvider{
 
     public Challenge returnChallenge() {
         String secret = HelperFunctions.randomString(6);
-        return new Challenge(gifCaptcha(secret),"gif",secret.toLowerCase());
+        return new Challenge(gifCaptcha(secret),"image/gif",secret.toLowerCase());
     }
 
     public boolean checkAnswer(String secret, String answer) {
diff --git a/src/main/java/lc/ShadowTextCaptcha.java b/src/main/java/lc/ShadowTextCaptcha.java
index 5221fae..dacfbfc 100644
--- a/src/main/java/lc/ShadowTextCaptcha.java
+++ b/src/main/java/lc/ShadowTextCaptcha.java
@@ -55,6 +55,6 @@ public class ShadowTextCaptcha implements ChallengeProvider{
 
     public Challenge returnChallenge() {
         String secret = HelperFunctions.randomString(6);
-        return new Challenge(shadowText(secret),"png",secret.toLowerCase());
+        return new Challenge(shadowText(secret),"image/png",secret.toLowerCase());
     }
 }