diff --git a/fuzz/decompress.cc b/fuzz/decompress.cc
index bad32524..022336aa 100644
--- a/fuzz/decompress.cc
+++ b/fuzz/decompress.cc
@@ -71,10 +71,10 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
     int w = width, h = height;
 
     /* Test non-default decompression options on the first iteration. */
-    if (pf == TJPF_RGB)
+    if (pfi == 0)
       flags |= TJFLAG_BOTTOMUP | TJFLAG_FASTUPSAMPLE | TJFLAG_FASTDCT;
     /* Test IDCT scaling on the second iteration. */
-    if (pf == TJPF_BGRX) {
+    else if (pfi == 1) {
       w = (width + 1) / 2;
       h = (height + 1) / 2;
     }
diff --git a/fuzz/decompress_yuv.cc b/fuzz/decompress_yuv.cc
index dc4620c5..a8a7302f 100644
--- a/fuzz/decompress_yuv.cc
+++ b/fuzz/decompress_yuv.cc
@@ -68,10 +68,10 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
     int w = width, h = height;
 
     /* Test non-default decompression options on the first iteration. */
-    if (pf == TJPF_RGB)
+    if (pfi == 0)
       flags |= TJFLAG_BOTTOMUP | TJFLAG_FASTUPSAMPLE | TJFLAG_FASTDCT;
     /* Test IDCT scaling on the second iteration. */
-    if (pf == TJPF_XRGB) {
+    else if (pfi == 1) {
       w = (width + 3) / 4;
       h = (height + 3) / 4;
     }