diff --git a/overviewer_core/src/composite.c b/overviewer_core/src/composite.c
index af97acd..32425cf 100644
--- a/overviewer_core/src/composite.c
+++ b/overviewer_core/src/composite.c
@@ -56,7 +56,9 @@ imaging_python_to_c(PyObject* obj) {
    in these composite functions -- even handles auto-sizing to src! */
 static inline void
 setup_source_destination(Imaging src, Imaging dest,
-                         int* sx, int* sy, int* dx, int* dy, int* xsize, int* ysize) {
+                         int32_t* sx, int32_t* sy,
+                         int32_t* dx, int32_t* dy,
+                         int32_t* xsize, int32_t* ysize) {
     /* handle negative/zero sizes appropriately */
     if (*xsize <= 0 || *ysize <= 0) {
         *xsize = src->xsize;
@@ -275,9 +277,11 @@ alpha_over_wrap(PyObject* self, PyObject* args) {
  * also, it multiplies instead of doing an over operation
  */
 PyObject*
-tint_with_mask(PyObject* dest, uint8_t sr, uint8_t sg,
-               uint8_t sb, uint8_t sa,
-               PyObject* mask, int32_t dx, int32_t dy, int32_t xsize, int32_t ysize) {
+tint_with_mask(PyObject* dest,
+               uint8_t sr, uint8_t sg, uint8_t sb, uint8_t sa,
+               PyObject* mask,
+               int32_t dx, int32_t dy,
+               int32_t xsize, int32_t ysize) {
     /* libImaging handles */
     Imaging imDest, imMask;
     /* cached blend properties */
@@ -378,7 +382,8 @@ draw_triangle(PyObject* dest, int32_t inclusive,
               uint8_t r1, uint8_t g1, uint8_t b1,
               int32_t x2, int32_t y2,
               uint8_t r2, uint8_t g2, uint8_t b2,
-              int32_t tux, int32_t tuy, int* touchups, uint32_t num_touchups) {
+              int32_t tux, int32_t tuy,
+              int32_t* touchups, uint32_t num_touchups) {
 
     /* destination image */
     Imaging imDest;
diff --git a/overviewer_core/src/endian.c b/overviewer_core/src/endian.c
index 37cb2d8..eac0b88 100644
--- a/overviewer_core/src/endian.c
+++ b/overviewer_core/src/endian.c
@@ -28,7 +28,7 @@ static int32_t endianness = UNKNOWN_ENDIAN;
 void init_endian(void) {
     /* figure out what our endianness is! */
     int16_t word = 0x0001;
-    char* byte = (char*)(&word);
+    uint8_t* byte = (uint8_t*)(&word);
     endianness = byte[0] ? LITTLE_ENDIAN : BIG_ENDIAN;
 }
 
diff --git a/overviewer_core/src/overviewer.h b/overviewer_core/src/overviewer.h
index 690e7ed..62c435e 100644
--- a/overviewer_core/src/overviewer.h
+++ b/overviewer_core/src/overviewer.h
@@ -70,7 +70,7 @@ PyObject* draw_triangle(PyObject* dest, int32_t inclusive,
                         uint8_t r1, uint8_t g1, uint8_t b1,
                         int32_t x2, int32_t y2,
                         uint8_t r2, uint8_t g2, uint8_t b2,
-                        int32_t tux, int32_t tuy, int* touchups, uint32_t num_touchups);
+                        int32_t tux, int32_t tuy, int32_t* touchups, uint32_t num_touchups);
 PyObject* resize_half(PyObject* dest, PyObject* src);
 PyObject* resize_half_wrap(PyObject* self, PyObject* args);
 
diff --git a/overviewer_core/src/rendermodes.h b/overviewer_core/src/rendermodes.h
index 4a05bf0..06b34e0 100644
--- a/overviewer_core/src/rendermodes.h
+++ b/overviewer_core/src/rendermodes.h
@@ -55,10 +55,10 @@ typedef struct {
     bool (*start)(void*, RenderState*, PyObject*);
     void (*finish)(void*, RenderState*);
     /* returns true to skip rendering this block because it's not visible */
-    bool (*occluded)(void*, RenderState*, int, int, int);
+    bool (*occluded)(void*, RenderState*, int32_t, int32_t, int32_t);
     /* returns true to skip rendering this block because the user doesn't
      * want it visible */
-    bool (*hidden)(void*, RenderState*, int, int, int);
+    bool (*hidden)(void*, RenderState*, int32_t, int32_t, int32_t);
     /* last two arguments are img and mask, from texture lookup */
     void (*draw)(void*, RenderState*, PyObject*, PyObject*, PyObject*);
 } RenderPrimitiveInterface;