diff --git a/engines/director/archive.cpp b/engines/director/archive.cpp
index 10a6b35f69a..8d4d4c3692f 100644
--- a/engines/director/archive.cpp
+++ b/engines/director/archive.cpp
@@ -640,15 +640,19 @@ bool RIFXArchive::readAfterburnerMap(Common::SeekableSubReadStreamEndian &stream
 	}
 	uint32 abmpLength = readVarInt(stream);
 	uint32 abmpCompressionType = readVarInt(stream);
-	uint32 abmpUncompLength = readVarInt(stream);
-	debug(3, "ABMP: length: %d compressionType: %d uncompressedLength: %d",
+	unsigned long abmpUncompLength = readVarInt(stream);
+	unsigned long abmpActualUncompLength = abmpUncompLength;
+	debug(3, "ABMP: length: %d compressionType: %d uncompressedLength: %lu",
 		abmpLength, abmpCompressionType, abmpUncompLength);
 
-	Common::SeekableReadStreamEndian *abmpStream = readZlibData(stream, abmpLength, abmpUncompLength, _isBigEndian);
+	Common::SeekableReadStreamEndian *abmpStream = readZlibData(stream, abmpLength, &abmpActualUncompLength, _isBigEndian);
 	if (!abmpStream) {
 		warning("RIFXArchive::readAfterburnerMap(): Could not uncompress ABMP");
 		return false;
 	}
+	if (abmpUncompLength != abmpActualUncompLength) {
+		warning("ABMP: Expected uncompressed length %lu but got length %lu", abmpUncompLength, abmpActualUncompLength);
+	}
 
 	if (ConfMan.getBool("dump_scripts")) {
 		Common::DumpFile out;
diff --git a/engines/director/util.cpp b/engines/director/util.cpp
index 57c0537b7fb..18856fc88ca 100644
--- a/engines/director/util.cpp
+++ b/engines/director/util.cpp
@@ -671,20 +671,20 @@ uint32 readVarInt(Common::SeekableReadStream &stream) {
 	return val;
 }
 
-Common::SeekableReadStreamEndian *readZlibData(Common::SeekableReadStream &stream, unsigned long len, unsigned long outLen, bool bigEndian) {
+Common::SeekableReadStreamEndian *readZlibData(Common::SeekableReadStream &stream, unsigned long len, unsigned long *outLen, bool bigEndian) {
 #ifdef USE_ZLIB
 	byte *in = (byte *)malloc(len);
-	byte *out = (byte *)malloc(outLen);
+	byte *out = (byte *)malloc(*outLen);
 	stream.read(in, len);
 
-	if (!Common::uncompress(out, &outLen, in, len)) {
+	if (!Common::uncompress(out, outLen, in, len)) {
 		free(in);
 		free(out);
 		return nullptr;
 	}
 
 	free(in);
-	return new Common::MemoryReadStreamEndian(out, outLen, bigEndian);
+	return new Common::MemoryReadStreamEndian(out, *outLen, bigEndian);
 # else
 	return nullptr;
 # endif
diff --git a/engines/director/util.h b/engines/director/util.h
index 7be84db5b3c..009291e33d9 100644
--- a/engines/director/util.h
+++ b/engines/director/util.h
@@ -78,7 +78,7 @@ private:
 
 uint32 readVarInt(Common::SeekableReadStream &stream);
 
-Common::SeekableReadStreamEndian *readZlibData(Common::SeekableReadStream &stream, unsigned long len, unsigned long outLen, bool bigEndian);
+Common::SeekableReadStreamEndian *readZlibData(Common::SeekableReadStream &stream, unsigned long len, unsigned long *outLen, bool bigEndian);
 
 } // End of namespace Director