diff --git a/src/libImaging/Convert.c b/src/libImaging/Convert.c
index 1ad1bdfb8..54ac02b6c 100644
--- a/src/libImaging/Convert.c
+++ b/src/libImaging/Convert.c
@@ -1706,10 +1706,10 @@ ImagingConvertTransparent(Imaging imIn, const char *mode, int r, int g, int b) {
         return (Imaging)ImagingError_ModeError();
     }
 
-    int rgbIn = strcmp(mode, "rgb") == 0;
-    int bitIn = strcmp(mode, "1") == 0;
-    int iIn = strcmp(mode, "I") == 0;
-    int lIn = strcmp(mode, "L") == 0;
+    int rgbIn = strcmp(imIn->mode, "rgb") == 0;
+    int bitIn = strcmp(imIn->mode, "1") == 0;
+    int iIn = strcmp(imIn->mode, "I") == 0;
+    int lIn = strcmp(imIn->mode, "L") == 0;
     int rgbaOut = strcmp(mode, "RGBA") == 0;
     int laOut = strcmp(mode, "LA") == 0;