diff --git a/include/a2_types.h b/include/a2_types.h
index be0037d..bff92e1 100644
--- a/include/a2_types.h
+++ b/include/a2_types.h
@@ -145,6 +145,7 @@ typedef enum {
   A2_DEFERR(LATEMESSAGE,	"API message arrived late to engine context")\
   A2_DEFERR(MANYARGS,		"Too many arguments to VM program")\
   \
+  A2_DEFERR(MSGOVERFLOW,	"API message buffer overflow")\
   A2_DEFERR(BUFOVERFLOW,	"Buffer overflow")\
   A2_DEFERR(BUFUNDERFLOW,	"Buffer underflow")\
   A2_DEFERR(DIVBYZERO,		"Division by zero")\
diff --git a/src/interface.c b/src/interface.c
index 2ea3e18..da78555 100644
--- a/src/interface.c
+++ b/src/interface.c
@@ -654,7 +654,7 @@ static A2_handle a2_API_Starta(A2_interface *i, A2_handle parent,
 		return am.b.start.voice;
 	if((res = a2_writemsgargs(st->fromapi, &am, argc, argv,
 			offsetof(A2_apimessage, b.start.a))))
-		return res;
+		return -res;
 	return am.b.start.voice;
 }
 
diff --git a/src/internals.h b/src/internals.h
index 41a4567..4d02747 100644
--- a/src/internals.h
+++ b/src/internals.h
@@ -920,7 +920,7 @@ static inline A2_event **a2_GetEventQueue(A2_state *st, A2_handle handle)
 	  case A2_TVOICE:
 		return &((A2_voice *)hi->d.data)->events;
 	  default:
-	  	return NULL;
+		return NULL;
 	}
 }
 
@@ -1057,7 +1057,7 @@ static inline A2_errors a2_writemsg(SFIFO *f, A2_apimessage *m, unsigned size)
 				"%d bytes (min: %d)", size, A2_APIREADSIZE);
 #endif
 	if(sfifo_Space(f) < size)
-		return A2_OVERFLOW;
+		return A2_MSGOVERFLOW;
 	m->size = size;
 	m->b.common.argc = 0;
 	if(sfifo_Write(f, m, size) != size)
@@ -1079,7 +1079,7 @@ static inline A2_errors a2_writemsgargs(SFIFO *f, A2_apimessage *m,
 	if(argc > A2_MAXARGS)
 		return A2_MANYARGS;
 	if(sfifo_Space(f) < size)
-		return A2_OVERFLOW;
+		return A2_MSGOVERFLOW;
 	m->size = size;
 	m->b.common.argc = argc;
 	memcpy((char *)m + argoffs, argv, argsize);