diff --git a/src/kits/app/Looper.cpp b/src/kits/app/Looper.cpp
index a769ef2d9b..a153429aac 100644
--- a/src/kits/app/Looper.cpp
+++ b/src/kits/app/Looper.cpp
@@ -38,7 +38,7 @@
 // debugging
 //#define DBG(x) x
 #define DBG(x)	;
-#define PRINT(x)	DBG({ printf("[%6ld] ", find_thread(NULL)); printf x; })
+#define PRINT(x)	DBG({ printf("[%6" B_PRId32 "] ", find_thread(NULL)); printf x; })
 
 /*
 #include <Autolock.h>
@@ -958,7 +958,7 @@ BLooper::_Lock(BLooper* looper, port_id port, bigtime_t timeout)
 		// Check for nested lock attempt
 		if (currentThread == looper->fOwner) {
 			++looper->fOwnerCount;
-			PRINT(("BLooper::_Lock() done 5: fOwnerCount: %ld\n", loop->fOwnerCount));
+			PRINT(("BLooper::_Lock() done 5: fOwnerCount: %ld\n", looper->fOwnerCount));
 			return B_OK;
 		}