diff --git a/src/org/thoughtcrime/securesms/crypto/ModernDecryptingPartInputStream.java b/src/org/thoughtcrime/securesms/crypto/ModernDecryptingPartInputStream.java
index e96da29dcf..e8c4e02c66 100644
--- a/src/org/thoughtcrime/securesms/crypto/ModernDecryptingPartInputStream.java
+++ b/src/org/thoughtcrime/securesms/crypto/ModernDecryptingPartInputStream.java
@@ -75,8 +75,9 @@ public class ModernDecryptingPartInputStream {
     for (;;) {
       int read = in.read(buffer, offset, buffer.length-offset);
 
-      if (read + offset < buffer.length) offset += read;
-      else                               return;
+      if (read == -1)                         throw new IOException("Prematurely reached end of stream!");
+      else if (read + offset < buffer.length) offset += read;
+      else                                    return;
     }
   }