diff --git a/src/libImaging/TiffDecode.c b/src/libImaging/TiffDecode.c
index b3a51f5b6..9b5916ac0 100644
--- a/src/libImaging/TiffDecode.c
+++ b/src/libImaging/TiffDecode.c
@@ -412,7 +412,7 @@ ImagingLibTiffDecode(
     UINT8 planes = 1;
     ImagingShuffler unpackers[4];
 
-    memset(unpackers, 0, sizeof(ImagingShuffler *) * 4);
+    memset(unpackers, 0, sizeof(ImagingShuffler) * 4);
 
     /* buffer is the encoded file, bytes is the length of the encoded file */
     /*     it all ends up in state->buffer, which is a uint8* from Imaging.h */