diff --git a/core/io/compression.cpp b/core/io/compression.cpp
index e04d1d16297..652f60966a5 100644
--- a/core/io/compression.cpp
+++ b/core/io/compression.cpp
@@ -104,19 +104,21 @@ int Compression::get_max_compressed_buffer_size(int p_src_size, Mode p_mode) {
 	ERR_FAIL_V(-1);
 }
 
-void Compression::decompress(uint8_t *p_dst, int p_dst_max_size, const uint8_t *p_src, int p_src_size, Mode p_mode) {
+int Compression::decompress(uint8_t *p_dst, int p_dst_max_size, const uint8_t *p_src, int p_src_size, Mode p_mode) {
 
 	switch (p_mode) {
 		case MODE_FASTLZ: {
 
+			int ret_size=0;
+
 			if (p_dst_max_size < 16) {
 				uint8_t dst[16];
-				fastlz_decompress(p_src, p_src_size, dst, 16);
+				ret_size = fastlz_decompress(p_src, p_src_size, dst, 16);
 				copymem(p_dst, dst, p_dst_max_size);
 			} else {
-				fastlz_decompress(p_src, p_src_size, p_dst, p_dst_max_size);
+				ret_size = fastlz_decompress(p_src, p_src_size, p_dst, p_dst_max_size);
 			}
-			return;
+			return ret_size;
 		} break;
 		case MODE_DEFLATE: {
 
@@ -127,7 +129,7 @@ void Compression::decompress(uint8_t *p_dst, int p_dst_max_size, const uint8_t *
 			strm.avail_in = 0;
 			strm.next_in = Z_NULL;
 			int err = inflateInit(&strm);
-			ERR_FAIL_COND(err != Z_OK);
+			ERR_FAIL_COND_V(err != Z_OK, -1);
 
 			strm.avail_in = p_src_size;
 			strm.avail_out = p_dst_max_size;
@@ -135,11 +137,12 @@ void Compression::decompress(uint8_t *p_dst, int p_dst_max_size, const uint8_t *
 			strm.next_out = p_dst;
 
 			err = inflate(&strm, Z_FINISH);
+			int total = strm.total_out;
 			inflateEnd(&strm);
-			ERR_FAIL_COND(err != Z_STREAM_END);
-			return;
+			ERR_FAIL_COND_V(err != Z_STREAM_END, -1);
+			return total;
 		} break;
 	}
 
-	ERR_FAIL();
+	ERR_FAIL_V(-1);
 }
diff --git a/core/io/compression.h b/core/io/compression.h
index b5f0db9e968..a982a074b1a 100644
--- a/core/io/compression.h
+++ b/core/io/compression.h
@@ -41,7 +41,7 @@ public:
 
 	static int compress(uint8_t *p_dst, const uint8_t *p_src, int p_src_size, Mode p_mode = MODE_FASTLZ);
 	static int get_max_compressed_buffer_size(int p_src_size, Mode p_mode = MODE_FASTLZ);
-	static void decompress(uint8_t *p_dst, int p_dst_max_size, const uint8_t *p_src, int p_src_size, Mode p_mode = MODE_FASTLZ);
+	static int decompress(uint8_t *p_dst, int p_dst_max_size, const uint8_t *p_src, int p_src_size, Mode p_mode = MODE_FASTLZ);
 
 	Compression();
 };