diff --git a/common/GNUfiles.mk b/common/GNUfiles.mk
index 14416f4e..58f901c6 100644
--- a/common/GNUfiles.mk
+++ b/common/GNUfiles.mk
@@ -3,6 +3,7 @@
 CFILES += \
 	common/areaevents.c \
 	common/control.c \
+	common/debug.c \
 	common/matrix.c \
 	common/shouldquit.c
 
diff --git a/common/debug.c b/common/debug.c
new file mode 100644
index 00000000..97280b47
--- /dev/null
+++ b/common/debug.c
@@ -0,0 +1,21 @@
+// 13 may 2016
+#include "../ui.h"
+#include "uipriv.h"
+
+void _implbug(const char *file, const char *line, const char *func, const char *format, ...)
+{
+	va_list ap;
+
+	va_start(ap, format);
+	realbug(file, line, func, "POSSIBLE IMPLEMENTATION BUG; CONTACT ANDLABS:\n", format, ap);
+	va_end(ap);
+}
+
+void _userbug(const char *file, const char *line, const char *func, const char *format, ...)
+{
+	va_list ap;
+
+	va_start(ap, format);
+	realbug(file, line, func, "You have a bug: ", format, ap);
+	va_end(ap);
+}
diff --git a/common/uipriv.h b/common/uipriv.h
index a36be4eb..e39bcf86 100644
--- a/common/uipriv.h
+++ b/common/uipriv.h
@@ -3,6 +3,7 @@
 extern "C" {
 #endif
 
+#include <stdarg.h>
 #include "controlsigs.h"
 
 extern uiInitOptions options;
@@ -12,6 +13,7 @@ extern void *uiAlloc(size_t, const char *);
 extern void *uiRealloc(void *, size_t, const char *);
 extern void uiFree(void *);
 
+extern void realbug(const char *file, const char *line, const char *func, const char *prefix, const char *format, va_list ap);
 #define _ns2(s) #s
 #define _ns(s) _ns2(s)
 extern void _implbug(const char *file, const char *line, const char *func, const char *format, ...);
diff --git a/darwin/GNUfiles.mk b/darwin/GNUfiles.mk
index 85d89615..1ddbeebc 100644
--- a/darwin/GNUfiles.mk
+++ b/darwin/GNUfiles.mk
@@ -11,9 +11,9 @@ MFILES += \
 	darwin/combobox.m \
 	darwin/control.m \
 	darwin/datetimepicker.m \
+	darwin/debug.m \
 	darwin/draw.m \
 	darwin/drawtext.m \
-	darwin/debug.m \
 	darwin/entry.m \
 	darwin/fontbutton.m \
 	darwin/group.m \
diff --git a/darwin/debug.m b/darwin/debug.m
index ec55a84b..87467add 100644
--- a/darwin/debug.m
+++ b/darwin/debug.m
@@ -3,7 +3,7 @@
 
 // TODO don't halt on release builds
 
-static void bug(const char *file, const char *line, const char *func, const char *prefix, const char *format, va_list ap)
+void realbug(const char *file, const char *line, const char *func, const char *prefix, const char *format, va_list ap)
 {
 	NSMutableString *str;
 	NSString *formatted;
@@ -17,21 +17,3 @@ static void bug(const char *file, const char *line, const char *func, const char
 	[str release];
 	__builtin_trap();
 }
-
-void _implbug(const char *file, const char *line, const char *func, const char *format, ...)
-{
-	va_list ap;
-
-	va_start(ap, format);
-	bug(file, line, func, "POSSIBLE IMPLEMENTATION BUG; CONTACT ANDLABS:\n", format, ap);
-	va_end(ap);
-}
-
-void _userbug(const char *file, const char *line, const char *func, const char *format, ...)
-{
-	va_list ap;
-
-	va_start(ap, format);
-	bug(file, line, func, "You have a bug: ", format, ap);
-	va_end(ap);
-}