diff --git a/src/_imaging.c b/src/_imaging.c
index e467777fe19..b17383ddd58 100644
--- a/src/_imaging.c
+++ b/src/_imaging.c
@@ -2204,25 +2204,25 @@ _transpose(ImagingObject *self, PyObject *args) {
     if (imOut) {
         switch (op) {
             case 0:
-                (void)ImagingFlipLeftRight(imOut, imIn);
+                ImagingFlipLeftRight(imOut, imIn);
                 break;
             case 1:
-                (void)ImagingFlipTopBottom(imOut, imIn);
+                ImagingFlipTopBottom(imOut, imIn);
                 break;
             case 2:
-                (void)ImagingRotate90(imOut, imIn);
+                ImagingRotate90(imOut, imIn);
                 break;
             case 3:
-                (void)ImagingRotate180(imOut, imIn);
+                ImagingRotate180(imOut, imIn);
                 break;
             case 4:
-                (void)ImagingRotate270(imOut, imIn);
+                ImagingRotate270(imOut, imIn);
                 break;
             case 5:
-                (void)ImagingTranspose(imOut, imIn);
+                ImagingTranspose(imOut, imIn);
                 break;
             case 6:
-                (void)ImagingTransverse(imOut, imIn);
+                ImagingTransverse(imOut, imIn);
                 break;
         }
     }
diff --git a/src/libImaging/Geometry.c b/src/libImaging/Geometry.c
index 198cad43bf2..35d9a47f0cf 100644
--- a/src/libImaging/Geometry.c
+++ b/src/libImaging/Geometry.c
@@ -14,24 +14,16 @@
 /* -------------------------------------------------------------------- */
 /* Transpose operations                                                 */
 
-Imaging
+void
 ImagingFlipLeftRight(Imaging imOut, Imaging imIn) {
     ImagingSectionCookie cookie;
     int x, y, xr;
-
-    if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
-    }
-
-    int xsize = imIn->xsize, ysize = imIn->ysize;
-    if (xsize != imOut->xsize || ysize != imOut->ysize) {
-        return (Imaging)ImagingError_Mismatch();
-    }
+    int xsize = imIn->xsize;
 
     ImagingCopyPalette(imOut, imIn);
 
 #define FLIP_LEFT_RIGHT(INT, image)         \
-    for (y = 0; y < ysize; y++) {           \
+    for (y = 0; y < imIn->ysize; y++) {     \
         INT *in = (INT *)imIn->image[y];    \
         INT *out = (INT *)imOut->image[y];  \
         xr = xsize - 1;                     \
@@ -55,23 +47,13 @@ ImagingFlipLeftRight(Imaging imOut, Imaging imIn) {
     ImagingSectionLeave(&cookie);
 
 #undef FLIP_LEFT_RIGHT
-
-    return imOut;
 }
 
-Imaging
+void
 ImagingFlipTopBottom(Imaging imOut, Imaging imIn) {
     ImagingSectionCookie cookie;
     int y, yr;
-
-    if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
-    }
-
     int ysize = imIn->ysize;
-    if (imIn->xsize != imOut->xsize || ysize != imOut->ysize) {
-        return (Imaging)ImagingError_Mismatch();
-    }
 
     ImagingCopyPalette(imOut, imIn);
 
@@ -83,24 +65,14 @@ ImagingFlipTopBottom(Imaging imOut, Imaging imIn) {
     }
 
     ImagingSectionLeave(&cookie);
-
-    return imOut;
 }
 
-Imaging
+void
 ImagingRotate90(Imaging imOut, Imaging imIn) {
     ImagingSectionCookie cookie;
     int x, y, xx, yy, xr, xxsize, yysize;
     int xxx, yyy, xxxsize, yyysize;
-
-    if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
-    }
-
     int xsize = imIn->xsize, ysize = imIn->ysize;
-    if (xsize != imOut->ysize || ysize != imOut->xsize) {
-        return (Imaging)ImagingError_Mismatch();
-    }
 
     ImagingCopyPalette(imOut, imIn);
 
@@ -145,24 +117,14 @@ ImagingRotate90(Imaging imOut, Imaging imIn) {
     ImagingSectionLeave(&cookie);
 
 #undef ROTATE_90
-
-    return imOut;
 }
 
-Imaging
+void
 ImagingTranspose(Imaging imOut, Imaging imIn) {
     ImagingSectionCookie cookie;
     int x, y, xx, yy, xxsize, yysize;
     int xxx, yyy, xxxsize, yyysize;
-
-    if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
-    }
-
     int xsize = imIn->xsize, ysize = imIn->ysize;
-    if (xsize != imOut->ysize || ysize != imOut->xsize) {
-        return (Imaging)ImagingError_Mismatch();
-    }
 
     ImagingCopyPalette(imOut, imIn);
 
@@ -206,24 +168,14 @@ ImagingTranspose(Imaging imOut, Imaging imIn) {
     ImagingSectionLeave(&cookie);
 
 #undef TRANSPOSE
-
-    return imOut;
 }
 
-Imaging
+void
 ImagingTransverse(Imaging imOut, Imaging imIn) {
     ImagingSectionCookie cookie;
     int x, y, xr, yr, xx, yy, xxsize, yysize;
     int xxx, yyy, xxxsize, yyysize;
-
-    if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
-    }
-
     int xsize = imIn->xsize, ysize = imIn->ysize;
-    if (xsize != imOut->ysize || ysize != imOut->xsize) {
-        return (Imaging)ImagingError_Mismatch();
-    }
 
     ImagingCopyPalette(imOut, imIn);
 
@@ -269,23 +221,13 @@ ImagingTransverse(Imaging imOut, Imaging imIn) {
     ImagingSectionLeave(&cookie);
 
 #undef TRANSVERSE
-
-    return imOut;
 }
 
-Imaging
+void
 ImagingRotate180(Imaging imOut, Imaging imIn) {
     ImagingSectionCookie cookie;
     int x, y, xr, yr;
-
-    if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
-    }
-
     int xsize = imIn->xsize, ysize = imIn->ysize;
-    if (xsize != imOut->xsize || ysize != imOut->ysize) {
-        return (Imaging)ImagingError_Mismatch();
-    }
 
     ImagingCopyPalette(imOut, imIn);
 
@@ -315,24 +257,14 @@ ImagingRotate180(Imaging imOut, Imaging imIn) {
     ImagingSectionLeave(&cookie);
 
 #undef ROTATE_180
-
-    return imOut;
 }
 
-Imaging
+void
 ImagingRotate270(Imaging imOut, Imaging imIn) {
     ImagingSectionCookie cookie;
     int x, y, xx, yy, yr, xxsize, yysize;
     int xxx, yyy, xxxsize, yyysize;
-
-    if (!imOut || !imIn || imIn->mode != imOut->mode) {
-        return (Imaging)ImagingError_ModeError();
-    }
-
     int xsize = imIn->xsize, ysize = imIn->ysize;
-    if (xsize != imOut->ysize || ysize != imOut->xsize) {
-        return (Imaging)ImagingError_Mismatch();
-    }
 
     ImagingCopyPalette(imOut, imIn);
 
@@ -377,8 +309,6 @@ ImagingRotate270(Imaging imOut, Imaging imIn) {
     ImagingSectionLeave(&cookie);
 
 #undef ROTATE_270
-
-    return imOut;
 }
 
 /* -------------------------------------------------------------------- */
diff --git a/src/libImaging/Imaging.h b/src/libImaging/Imaging.h
index 20f74b519a3..4b23003db0a 100644
--- a/src/libImaging/Imaging.h
+++ b/src/libImaging/Imaging.h
@@ -330,9 +330,9 @@ extern Imaging
 ImagingFillRadialGradient(ModeID mode);
 extern Imaging
 ImagingFilter(Imaging im, int xsize, int ysize, const FLOAT32 *kernel, FLOAT32 offset);
-extern Imaging
+extern void
 ImagingFlipLeftRight(Imaging imOut, Imaging imIn);
-extern Imaging
+extern void
 ImagingFlipTopBottom(Imaging imOut, Imaging imIn);
 extern Imaging
 ImagingGaussianBlur(
@@ -375,15 +375,15 @@ extern Imaging
 ImagingPutBand(Imaging im, Imaging imIn, int band);
 extern Imaging
 ImagingRankFilter(Imaging im, int size, int rank);
-extern Imaging
+extern void
 ImagingRotate90(Imaging imOut, Imaging imIn);
-extern Imaging
+extern void
 ImagingRotate180(Imaging imOut, Imaging imIn);
-extern Imaging
+extern void
 ImagingRotate270(Imaging imOut, Imaging imIn);
-extern Imaging
+extern void
 ImagingTranspose(Imaging imOut, Imaging imIn);
-extern Imaging
+extern void
 ImagingTransverse(Imaging imOut, Imaging imIn);
 extern Imaging
 ImagingResample(Imaging imIn, int xsize, int ysize, int filter, float box[4]);