diff --git a/common/errors.c b/common/errors.c
index 91bdcfd8..b6c6a273 100644
--- a/common/errors.c
+++ b/common/errors.c
@@ -30,7 +30,7 @@ void uiprivInternalError(const char *fmt, ...)
 }
 
 static const char *messages[uiprivNumProgrammerErrors] = {
-	[uiprivProgrammerErrorWrongStructSize] = "wrong size %zu for %s",
+	[uiprivProgrammerErrorWrongStructSize] = "wrong size %" uiprivSizetPrintf " for %s",
 	[uiprivProgrammerErrorIndexOutOfRange] = "index %d out of range in %s()",
 	[uiprivProgrammerErrorNullPointer] = "invalid null pointer for %s passed into %s()",
 	[uiprivProgrammerErrorIntIDNotFound] = "%s identifier %d not found in %s()",
diff --git a/common/uipriv.h b/common/uipriv.h
index eb5ca28e..a64633bd 100644
--- a/common/uipriv.h
+++ b/common/uipriv.h
@@ -11,6 +11,13 @@ extern "C" {
 #define uiprivFunc __func__
 #endif
 
+// TODO WHY IS THIS NEEDED?!?!?!?!!?!??!Q https://stackoverflow.com/questions/15610053/correct-printf-format-specifier-for-size-t-zu-or-iu SAYS THAT VS2013 DOES SUPPORT %zu
+#ifdef _MSC_VER
+#define uiprivSizetPrintf "Iu"
+#else
+#define uiprivSizetPrintf "zu"
+#endif
+
 // init.c
 extern const char **uiprivSysInitErrors(void);
 extern int uiprivSysInit(void *options, uiInitError *err);