diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
index 8fb5fc2..a40b681 100644
--- a/Modules/_collectionsmodule.c
+++ b/Modules/_collectionsmodule.c
@@ -2388,7 +2388,7 @@
             return self;
         }
         PyErr_Format(PyExc_TypeError,
-                     "descriptor for index '%d' for tuple subclasses "
+                     "descriptor for index '%zd' for tuple subclasses "
                      "doesn't apply to '%s' object",
                      index,
                      obj->ob_type->tp_name);
diff --git a/Modules/_ctypes/callbacks.c b/Modules/_ctypes/callbacks.c
index c1e9b72..2b7cb06 100644
--- a/Modules/_ctypes/callbacks.c
+++ b/Modules/_ctypes/callbacks.c
@@ -165,14 +165,14 @@
         if (cnv)
             dict = PyType_stgdict(cnv);
         else {
-            PrintError("Getting argument converter %d\n", i);
+            PrintError("Getting argument converter %zd\n", i);
             goto Done;
         }
 
         if (dict && dict->getfunc && !_ctypes_simple_instance(cnv)) {
             PyObject *v = dict->getfunc(*pArgs, dict->size);
             if (!v) {
-                PrintError("create argument %d:\n", i);
+                PrintError("create argument %zd:\n", i);
                 Py_DECREF(cnv);
                 goto Done;
             }
@@ -186,14 +186,14 @@
             /* Hm, shouldn't we use PyCData_AtAddress() or something like that instead? */
             CDataObject *obj = (CDataObject *)_PyObject_CallNoArg(cnv);
             if (!obj) {
-                PrintError("create argument %d:\n", i);
+                PrintError("create argument %zd:\n", i);
                 Py_DECREF(cnv);
                 goto Done;
             }
             if (!CDataObject_Check(obj)) {
                 Py_DECREF(obj);
                 Py_DECREF(cnv);
-                PrintError("unexpected result of create argument %d:\n", i);
+                PrintError("unexpected result of create argument %zd:\n", i);
                 goto Done;
             }
             memcpy(obj->b_ptr, *pArgs, dict->size);
@@ -204,7 +204,7 @@
         } else {
             PyErr_SetString(PyExc_TypeError,
                             "cannot build parameter");
-            PrintError("Parsing argument %d\n", i);
+            PrintError("Parsing argument %zd\n", i);
             Py_DECREF(cnv);
             goto Done;
         }
diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index 9bcc955..d91e846 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -1131,20 +1131,20 @@
             converter = PyTuple_GET_ITEM(argtypes, i);
             v = PyObject_CallFunctionObjArgs(converter, arg, NULL);
             if (v == NULL) {
-                _ctypes_extend_error(PyExc_ArgError, "argument %d: ", i+1);
+                _ctypes_extend_error(PyExc_ArgError, "argument %zd: ", i+1);
                 goto cleanup;
             }
 
             err = ConvParam(v, i+1, pa);
             Py_DECREF(v);
             if (-1 == err) {
-                _ctypes_extend_error(PyExc_ArgError, "argument %d: ", i+1);
+                _ctypes_extend_error(PyExc_ArgError, "argument %zd: ", i+1);
                 goto cleanup;
             }
         } else {
             err = ConvParam(arg, i+1, pa);
             if (-1 == err) {
-                _ctypes_extend_error(PyExc_ArgError, "argument %d: ", i+1);
+                _ctypes_extend_error(PyExc_ArgError, "argument %zd: ", i+1);
                 goto cleanup; /* leaking ? */
             }
         }
diff --git a/Modules/_ctypes/malloc_closure.c b/Modules/_ctypes/malloc_closure.c
index 248c6a6..8ad7649 100644
--- a/Modules/_ctypes/malloc_closure.c
+++ b/Modules/_ctypes/malloc_closure.c
@@ -76,7 +76,7 @@
 
 #ifdef MALLOC_CLOSURE_DEBUG
     printf("block at %p allocated (%d bytes), %d ITEMs\n",
-           item, count * sizeof(ITEM), count);
+           item, count * (int)sizeof(ITEM), count);
 #endif
     /* put them into the free list */
     for (i = 0; i < count; ++i) {
diff --git a/Modules/_io/winconsoleio.c b/Modules/_io/winconsoleio.c
index dd0997a..70a723e 100644
--- a/Modules/_io/winconsoleio.c
+++ b/Modules/_io/winconsoleio.c
@@ -725,7 +725,7 @@
 
     if (u8n) {
         PyErr_Format(PyExc_SystemError,
-            "Buffer had room for %d bytes but %d bytes required",
+            "Buffer had room for %zd bytes but %u bytes required",
             len, u8n);
         return -1;
     }
diff --git a/Modules/_localemodule.c b/Modules/_localemodule.c
index 96ca68a..036bdb3 100644
--- a/Modules/_localemodule.c
+++ b/Modules/_localemodule.c
@@ -392,7 +392,7 @@
     char encoding[20];
     char locale[100];
 
-    PyOS_snprintf(encoding, sizeof(encoding), "cp%d", GetACP());
+    PyOS_snprintf(encoding, sizeof(encoding), "cp%u", GetACP());
 
     if (GetLocaleInfo(LOCALE_USER_DEFAULT,
                       LOCALE_SISO639LANGNAME,
diff --git a/Modules/_lzmamodule.c b/Modules/_lzmamodule.c
index b5f9561..18bc3dc 100644
--- a/Modules/_lzmamodule.c
+++ b/Modules/_lzmamodule.c
@@ -219,7 +219,7 @@
 
     if (lzma_lzma_preset(options, preset)) {
         PyMem_Free(options);
-        PyErr_Format(Error, "Invalid compression preset: %d", preset);
+        PyErr_Format(Error, "Invalid compression preset: %u", preset);
         return NULL;
     }
 
@@ -622,7 +622,7 @@
         lzma_options_lzma options;
 
         if (lzma_lzma_preset(&options, preset)) {
-            PyErr_Format(Error, "Invalid compression preset: %d", preset);
+            PyErr_Format(Error, "Invalid compression preset: %u", preset);
             return -1;
         }
         lzret = lzma_alone_encoder(lzs, &options);
diff --git a/Modules/_multiprocessing/semaphore.c b/Modules/_multiprocessing/semaphore.c
index bb7219e..cbcc64c 100644
--- a/Modules/_multiprocessing/semaphore.c
+++ b/Modules/_multiprocessing/semaphore.c
@@ -141,7 +141,7 @@
     default:
         PyErr_Format(PyExc_RuntimeError, "WaitForSingleObject() or "
                      "WaitForMultipleObjects() gave unrecognized "
-                     "value %d", res);
+                     "value %u", res);
         return NULL;
     }
 }
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index 0e720e2..f2ce7fa 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -3347,7 +3347,7 @@
 #if HAVE_ALPN
     if ((size_t)protos->len > UINT_MAX) {
         PyErr_Format(PyExc_OverflowError,
-            "protocols longer than %d bytes", UINT_MAX);
+            "protocols longer than %u bytes", UINT_MAX);
         return NULL;
     }
 
diff --git a/Modules/binascii.c b/Modules/binascii.c
index 19589f9..2e71ab9 100644
--- a/Modules/binascii.c
+++ b/Modules/binascii.c
@@ -520,7 +520,7 @@
             */
             PyErr_Format(Error,
                          "Invalid base64-encoded string: "
-                         "number of data characters (%d) cannot be 1 more "
+                         "number of data characters (%zd) cannot be 1 more "
                          "than a multiple of 4",
                          (bin_data - bin_data_start) / 3 * 4 + 1);
         } else {
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 8c3c2fa..1120f6b 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -4198,7 +4198,7 @@
             break;
         default:
             PyErr_Format(PyExc_TypeError,
-                         "sendto() takes 2 or 3 arguments (%d given)",
+                         "sendto() takes 2 or 3 arguments (%zd given)",
                          arglen);
             return NULL;
     }
@@ -4741,7 +4741,7 @@
         return PyLong_FromUnsignedLong(recv); }
 #endif
     default:
-        PyErr_Format(PyExc_ValueError, "invalid ioctl command %d", cmd);
+        PyErr_Format(PyExc_ValueError, "invalid ioctl command %lu", cmd);
         return NULL;
     }
 }