diff --git a/Sane/_sane.c b/Sane/_sane.c
index b424015a8..2001be421 100644
--- a/Sane/_sane.c
+++ b/Sane/_sane.c
@@ -408,7 +408,6 @@ static PyObject *
 SaneDev_set_auto_option(SaneDevObject *self, PyObject *args)
 {
   SANE_Status st;
-  const SANE_Option_Descriptor *d;
   SANE_Int i;
   int n;
   
@@ -419,7 +418,6 @@ SaneDev_set_auto_option(SaneDevObject *self, PyObject *args)
       PyErr_SetString(ErrorObject, "SaneDev object is closed");
       return NULL;
     }
-  d=sane_get_option_descriptor(self->h, n);
   st=sane_control_option(self->h, n, SANE_ACTION_SET_AUTO,
 			 NULL, &i);
   if (st) {return PySane_Error(st);}
diff --git a/Tk/tkImaging.c b/Tk/tkImaging.c
index 4234a7d2b..319645d56 100644
--- a/Tk/tkImaging.c
+++ b/Tk/tkImaging.c
@@ -48,9 +48,8 @@
    for the Tcl_CreateCommand command. */
 #define USE_COMPAT_CONST
 
-#include "tk.h"
-
 #include "Imaging.h"
+#include "tk.h"
 
 #include <stdlib.h>
 
diff --git a/_webp.c b/_webp.c
index 84418980c..cf53ff252 100644
--- a/_webp.c
+++ b/_webp.c
@@ -20,7 +20,7 @@ PyObject* WebPEncodeRGB_wrapper(PyObject* self, PyObject* args)
         return Py_None;
     }
 
-    PyBytes_AsStringAndSize((PyObject *) rgb_string, &rgb, &size);
+    PyBytes_AsStringAndSize((PyObject *) rgb_string, (char**)&rgb, &size);
 
     if (stride * height > size) {
         Py_INCREF(Py_None);
@@ -29,7 +29,7 @@ PyObject* WebPEncodeRGB_wrapper(PyObject* self, PyObject* args)
 
     ret_size = WebPEncodeRGB(rgb, width, height, stride, quality_factor, &output);
     if (ret_size > 0) {
-        PyObject *ret = PyBytes_FromStringAndSize(output, ret_size);
+        PyObject *ret = PyBytes_FromStringAndSize((char*)output, ret_size);
         free(output);
         return ret;
     }
@@ -41,7 +41,6 @@ PyObject* WebPEncodeRGB_wrapper(PyObject* self, PyObject* args)
 PyObject* WebPDecodeRGB_wrapper(PyObject* self, PyObject* args)
 {
     PyBytesObject *webp_string;
-    float quality_factor;
     int width;
     int height;
     uint8_t *webp;
@@ -54,11 +53,11 @@ PyObject* WebPDecodeRGB_wrapper(PyObject* self, PyObject* args)
         return Py_None;
     }
 
-    PyBytes_AsStringAndSize((PyObject *) webp_string, &webp, &size);
+    PyBytes_AsStringAndSize((PyObject *) webp_string, (char**)&webp, &size);
 
     output = WebPDecodeRGB(webp, size, &width, &height);
 
-    ret = PyBytes_FromStringAndSize(output, width * height * 3);
+    ret = PyBytes_FromStringAndSize((char*)output, width * height * 3);
     free(output);
     return Py_BuildValue("Sii", ret, width, height);
 }
@@ -90,7 +89,6 @@ PyInit__webp(void) {
 PyMODINIT_FUNC
 init_webp()
 {
-    PyObject* m;
-    m = Py_InitModule("_webp", webpMethods);
+    Py_InitModule("_webp", webpMethods);
 }
 #endif
diff --git a/libImaging/JpegEncode.c b/libImaging/JpegEncode.c
index 1caa50de5..221f8ccfa 100644
--- a/libImaging/JpegEncode.c
+++ b/libImaging/JpegEncode.c
@@ -221,7 +221,7 @@ ImagingJpegEncode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
             context->extra_offset = context->extra_size;
         //add exif header
         if (context->rawExifLen > 0)
-            jpeg_write_marker(&context->cinfo, JPEG_APP0+1, context->rawExif, context->rawExifLen);
+            jpeg_write_marker(&context->cinfo, JPEG_APP0+1, (unsigned char*)context->rawExif, context->rawExifLen);
 
 	    break;
 	default:
@@ -229,7 +229,7 @@ ImagingJpegEncode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
 	    jpeg_start_compress(&context->cinfo, TRUE);
         //add exif header
         if (context->rawExifLen > 0)
-            jpeg_write_marker(&context->cinfo, JPEG_APP0+1, context->rawExif, context->rawExifLen);
+            jpeg_write_marker(&context->cinfo, JPEG_APP0+1, (unsigned char*)context->rawExif, context->rawExifLen);
 
         break;
 	}