diff -r 0acc5626a578 Modules/_cursesmodule.c
--- a/Modules/_cursesmodule.c	Tue Oct 23 22:50:11 2012 +0100
+++ b/Modules/_cursesmodule.c	Wed Oct 24 13:36:36 2012 +0200
@@ -1713,7 +1713,11 @@
         remove(fn);
         return res;
     }
-    fseek(fp, 0, 0);
+    if (fseek(fp, 0, 0) == -1) {
+        fclose(fp);
+        remove(fn);
+        return PyErr_SetFromErrnoWithFilename(PyExc_IOError, fn);
+    }
     while (1) {
         char buf[BUFSIZ];
         Py_ssize_t n = fread(buf, 1, BUFSIZ, fp);
@@ -2293,7 +2297,11 @@
         return PyErr_SetFromErrnoWithFilename(PyExc_IOError, fn);
     }
     Py_DECREF(data);
-    fseek(fp, 0, 0);
+    if (fseek(fp, 0, 0) == -1) {
+        fclose(fp);
+        remove(fn);
+        return PyErr_SetFromErrnoWithFilename(PyExc_IOError, fn);
+    }
     win = getwin(fp);
     fclose(fp);
     remove(fn);