diff --git a/src/_imaging.c b/src/_imaging.c
index cc782698245..8eba25970b1 100644
--- a/src/_imaging.c
+++ b/src/_imaging.c
@@ -2042,7 +2042,7 @@ _resize(ImagingObject *self, PyObject *args) {
 
         imOut = ImagingNewDirty(imIn->mode, xsize, ysize);
 
-        imOut = ImagingTransform(
+        ImagingTransform(
             imOut, imIn, IMAGING_TRANSFORM_AFFINE, 0, 0, xsize, ysize, a, filter, 1
         );
     } else {
@@ -2167,13 +2167,13 @@ _transform(ImagingObject *self, PyObject *args) {
         return NULL;
     }
 
-    imOut = ImagingTransform(
+    int error = ImagingTransform(
         self->image, imagep->image, method, x0, y0, x1, y1, a, filter, fill
     );
 
     free(a);
 
-    if (!imOut) {
+    if (error) {
         return NULL;
     }
 
diff --git a/src/libImaging/Geometry.c b/src/libImaging/Geometry.c
index 198cad43bf2..aa4fd655ffb 100644
--- a/src/libImaging/Geometry.c
+++ b/src/libImaging/Geometry.c
@@ -779,7 +779,7 @@ getfilter(Imaging im, int filterid) {
 
 /* transformation engines */
 
-Imaging
+int
 ImagingGenericTransform(
     Imaging imOut,
     Imaging imIn,
@@ -801,12 +801,14 @@ ImagingGenericTransform(
     double xx, yy;
 
     if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
+        ImagingError_ModeError();
+        return -1;
     }
 
     ImagingTransformFilter filter = getfilter(imIn, filterid);
     if (!filter) {
-        return (Imaging)ImagingError_ValueError("bad filter number");
+        ImagingError_ValueError("bad filter number");
+        return -1;
     }
 
     ImagingCopyPalette(imOut, imIn);
@@ -841,10 +843,10 @@ ImagingGenericTransform(
 
     ImagingSectionLeave(&cookie);
 
-    return imOut;
+    return 0;
 }
 
-static Imaging
+static int
 ImagingScaleAffine(
     Imaging imOut, Imaging imIn, int x0, int y0, int x1, int y1, double a[6], int fill
 ) {
@@ -858,7 +860,8 @@ ImagingScaleAffine(
     int *xintab;
 
     if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
+        ImagingError_ModeError();
+        return -1;
     }
 
     ImagingCopyPalette(imOut, imIn);
@@ -883,7 +886,8 @@ ImagingScaleAffine(
     xintab = (int *)calloc(out_xsize, sizeof(int));
     if (!xintab) {
         ImagingDelete(imOut);
-        return (Imaging)ImagingError_MemoryError();
+        ImagingError_MemoryError();
+        return -1;
     }
 
     xo = a[2] + a[0] * 0.5;
@@ -936,7 +940,7 @@ ImagingScaleAffine(
 
     free(xintab);
 
-    return imOut;
+    return 0;
 }
 
 static inline int
@@ -947,7 +951,7 @@ check_fixed(double a[6], int x, int y) {
     );
 }
 
-static inline Imaging
+static inline int
 affine_fixed(
     Imaging imOut,
     Imaging imIn,
@@ -1022,10 +1026,10 @@ affine_fixed(
 
 #undef AFFINE_TRANSFORM_FIXED
 
-    return imOut;
+    return 0;
 }
 
-Imaging
+int
 ImagingTransformAffine(
     Imaging imOut,
     Imaging imIn,
@@ -1048,7 +1052,8 @@ ImagingTransformAffine(
     double xo, yo;
 
     if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
+        ImagingError_ModeError();
+        return -1;
     }
 
     if (filterid || imIn->type == IMAGING_TYPE_I16) {
@@ -1131,10 +1136,10 @@ ImagingTransformAffine(
 
 #undef AFFINE_TRANSFORM
 
-    return imOut;
+    return 0;
 }
 
-Imaging
+int
 ImagingTransform(
     Imaging imOut,
     Imaging imIn,
@@ -1162,7 +1167,8 @@ ImagingTransform(
             transform = quad_transform;
             break;
         default:
-            return (Imaging)ImagingError_ValueError("bad transform method");
+            ImagingError_ValueError("bad transform method");
+            return -1;
     }
 
     return ImagingGenericTransform(
diff --git a/src/libImaging/Imaging.h b/src/libImaging/Imaging.h
index 20f74b519a3..455d9c5706f 100644
--- a/src/libImaging/Imaging.h
+++ b/src/libImaging/Imaging.h
@@ -389,7 +389,7 @@ extern Imaging
 ImagingResample(Imaging imIn, int xsize, int ysize, int filter, float box[4]);
 extern Imaging
 ImagingReduce(Imaging imIn, int xscale, int yscale, int box[4]);
-extern Imaging
+extern int
 ImagingTransform(
     Imaging imOut,
     Imaging imIn,