diff --git a/Modules/_ctypes/stgdict.c b/Modules/_ctypes/stgdict.c
index aac073f..7db3e0f 100644
--- a/Modules/_ctypes/stgdict.c
+++ b/Modules/_ctypes/stgdict.c
@@ -408,6 +408,7 @@
 		ffi_ofs = 0;
 	}
 
+	assert(stgdict->format == NULL);
 	if (isStruct && !isPacked) {
 		stgdict->format = alloc_format_string(NULL, "T{");
 	} else {
@@ -527,7 +528,9 @@
 #undef realdict
 
 	if (isStruct && !isPacked) {
+		char *ptr = stgdict->format;
 		stgdict->format = alloc_format_string(stgdict->format, "}");
+		PyMem_Free(ptr);
 		if (stgdict->format == NULL)
 			return -1;
 	}
diff --git a/Modules/_fileio.c b/Modules/_fileio.c
index f0c8fed..ec123e8 100644
--- a/Modules/_fileio.c
+++ b/Modules/_fileio.c
@@ -278,6 +278,7 @@
 	ret = -1;
 
  done:
+	PyMem_Free(name);
 	return ret;
 }
 
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
index e190429..8860b39 100644
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -796,7 +796,8 @@
 #if defined (HAVE_SETITIMER) || defined (HAVE_GETITIMER)
     ItimerError = PyErr_NewException("signal.ItimerError", 
          PyExc_IOError, NULL);
-    PyDict_SetItemString(d, "ItimerError", ItimerError);
+    if (ItimerError != NULL)
+    	PyDict_SetItemString(d, "ItimerError", ItimerError);
 #endif
 
     if (PyErr_Occurred()) {