diff --git a/image/decoders/nsICODecoder.cpp b/image/decoders/nsICODecoder.cpp
index b630633110fb..18a11473f6ea 100644
--- a/image/decoders/nsICODecoder.cpp
+++ b/image/decoders/nsICODecoder.cpp
@@ -280,7 +280,7 @@ nsICODecoder::SniffResource(const char* aData)
     // Read in the rest of the PNG unbuffered.
     size_t toRead = mDirEntry.mBytesInRes - PNGSIGNATURESIZE;
     return Transition::ToUnbuffered(ICOState::FINISHED_RESOURCE,
-                                    ICOState::READ_RESOURCE,
+                                    ICOState::READ_PNG,
                                     toRead);
   } else {
     // Make sure we have a sane size for the bitmap information header.
@@ -299,13 +299,13 @@ nsICODecoder::SniffResource(const char* aData)
 }
 
 LexerTransition<ICOState>
-nsICODecoder::ReadResource(const char* aData, uint32_t aLen)
+nsICODecoder::ReadPNG(const char* aData, uint32_t aLen)
 {
   if (!WriteToContainedDecoder(aData, aLen)) {
     return Transition::TerminateFailure();
   }
 
-  return Transition::ContinueUnbuffered(ICOState::READ_RESOURCE);
+  return Transition::ContinueUnbuffered(ICOState::READ_PNG);
 }
 
 LexerTransition<ICOState>
@@ -365,10 +365,20 @@ nsICODecoder::ReadBIH(const char* aData)
 
   // Read in the rest of the BMP unbuffered.
   return Transition::ToUnbuffered(afterBMPState,
-                                  ICOState::READ_RESOURCE,
+                                  ICOState::READ_BMP,
                                   bmpDataLength);
 }
 
+LexerTransition<ICOState>
+nsICODecoder::ReadBMP(const char* aData, uint32_t aLen)
+{
+  if (!WriteToContainedDecoder(aData, aLen)) {
+    return Transition::TerminateFailure();
+  }
+
+  return Transition::ContinueUnbuffered(ICOState::READ_BMP);
+}
+
 LexerTransition<ICOState>
 nsICODecoder::PrepareForMask()
 {
@@ -558,10 +568,12 @@ nsICODecoder::DoDecode(SourceBufferIterator& aIterator, IResumable* aOnResume)
         return Transition::To(ICOState::SNIFF_RESOURCE, PNGSIGNATURESIZE);
       case ICOState::SNIFF_RESOURCE:
         return SniffResource(aData);
-      case ICOState::READ_RESOURCE:
-        return ReadResource(aData, aLength);
+      case ICOState::READ_PNG:
+        return ReadPNG(aData, aLength);
       case ICOState::READ_BIH:
         return ReadBIH(aData);
+      case ICOState::READ_BMP:
+        return ReadBMP(aData, aLength);
       case ICOState::PREPARE_FOR_MASK:
         return PrepareForMask();
       case ICOState::READ_MASK_ROW:
diff --git a/image/decoders/nsICODecoder.h b/image/decoders/nsICODecoder.h
index 3fa5a31500dc..75206db333be 100644
--- a/image/decoders/nsICODecoder.h
+++ b/image/decoders/nsICODecoder.h
@@ -27,8 +27,9 @@ enum class ICOState
   SKIP_TO_RESOURCE,
   FOUND_RESOURCE,
   SNIFF_RESOURCE,
-  READ_RESOURCE,
+  READ_PNG,
   READ_BIH,
+  READ_BMP,
   PREPARE_FOR_MASK,
   READ_MASK_ROW,
   FINISH_MASK,
@@ -92,8 +93,9 @@ private:
   LexerTransition<ICOState> ReadHeader(const char* aData);
   LexerTransition<ICOState> ReadDirEntry(const char* aData);
   LexerTransition<ICOState> SniffResource(const char* aData);
-  LexerTransition<ICOState> ReadResource(const char* aData, uint32_t aLen);
+  LexerTransition<ICOState> ReadPNG(const char* aData, uint32_t aLen);
   LexerTransition<ICOState> ReadBIH(const char* aData);
+  LexerTransition<ICOState> ReadBMP(const char* aData, uint32_t aLen);
   LexerTransition<ICOState> PrepareForMask();
   LexerTransition<ICOState> ReadMaskRow(const char* aData);
   LexerTransition<ICOState> FinishMask();