diff --git a/tests/integration.c b/tests/integration.c
index 3194de3..b1945b5 100644
--- a/tests/integration.c
+++ b/tests/integration.c
@@ -875,8 +875,9 @@ static int generate_test_wav(const char *path, unsigned sample_rate, unsigned du
     unsigned char header[44];
     memset(header, 0, 44);
     memcpy(header, "RIFF", 4);
-    header[4] = file_size & 0xff; header[5] = (file_size>>8)&0xff;
-    header[6] = (file_size>>16)&0xff; header[7] = (file_size>>24)&0xff;
+    unsigned chunk_size = file_size - 8;
+    header[4] = chunk_size & 0xff; header[5] = (chunk_size>>8)&0xff;
+    header[6] = (chunk_size>>16)&0xff; header[7] = (chunk_size>>24)&0xff;
     memcpy(header+8, "WAVE", 4);
     memcpy(header+12, "fmt ", 4);
     header[16]=16; header[17]=0; header[18]=0; header[19]=0;