diff --git a/common/control.c b/common/control.c
index 3b5b8286..98cb94aa 100644
--- a/common/control.c
+++ b/common/control.c
@@ -57,14 +57,14 @@ void uiControlDisable(uiControl *c)
 	(*(c->Disable))(c);
 }
 
-#define uiControlSignature 0x7569436F
+#define uiprivControlSignature 0x7569436F
 
 uiControl *uiAllocControl(size_t size, uint32_t OSsig, uint32_t typesig, const char *typenamestr)
 {
 	uiControl *c;
 
 	c = (uiControl *) uiprivAlloc(size, typenamestr);
-	c->Signature = uiControlSignature;
+	c->Signature = uiprivControlSignature;
 	c->OSSignature = OSsig;
 	c->TypeSignature = typesig;
 	return c;
diff --git a/common/shouldquit.c b/common/shouldquit.c
index dddd879c..df57b6c5 100644
--- a/common/shouldquit.c
+++ b/common/shouldquit.c
@@ -8,7 +8,7 @@ static int defaultOnShouldQuit(void *data)
 }
 
 static int (*onShouldQuit)(void *) = defaultOnShouldQuit;
-static void *onShouldQuitData;
+static void *onShouldQuitData = NULL;
 
 void uiOnShouldQuit(int (*f)(void *), void *data)
 {