diff --git a/extra/alien/marshall/syntax/syntax-tests.factor b/extra/alien/marshall/syntax/syntax-tests.factor
index 3945924a57..68e6f7aff8 100644
--- a/extra/alien/marshall/syntax/syntax-tests.factor
+++ b/extra/alien/marshall/syntax/syntax-tests.factor
@@ -10,7 +10,8 @@ C-LIBRARY: test
 C-INCLUDE: <stdlib.h>
 C-INCLUDE: <string.h>
 
-C-TYPEDEF: char bool
+! This used to typedef 'bool' but that's bad for PowerPC where its really an int
+C-TYPEDEF: char mybool
 
 CM-FUNCTION: void outarg1 ( int* a )
     *a += 2;
@@ -38,7 +39,7 @@ CM-FUNCTION: void change_time ( double hours, sundial* d )
     d->wedge.degrees = hours * 30;
 ;
 
-CM-FUNCTION: bool c_not ( bool p )
+CM-FUNCTION: mybool c_not ( mybool p )
     return !p;
 ;