diff --git a/C/text.c b/C/text.c
index 9f732ffb7..33ec47615 100644
--- a/C/text.c
+++ b/C/text.c
@@ -320,13 +320,16 @@ Yap_ListToBuffer(void *buf, Term t, seq_tv_t *inp, int *widep USES_REGS)
 
 static yap_error_number 
 gen_type_error(int flags) {
-  if (flags & (YAP_STRING_STRING|YAP_STRING_ATOM|YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_ATOMS_CODES|YAP_STRING_BIG))
+  if ((flags & (YAP_STRING_STRING|YAP_STRING_ATOM|YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_ATOMS_CODES|YAP_STRING_BIG)) ==
+      (YAP_STRING_STRING|YAP_STRING_ATOM|YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_ATOMS_CODES|YAP_STRING_BIG))
     return TYPE_ERROR_TEXT;
-  if (flags & (YAP_STRING_STRING|YAP_STRING_ATOM|YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_BIG))
+  if ((flags & (YAP_STRING_STRING|YAP_STRING_ATOM|YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_BIG)) ==
+      (YAP_STRING_STRING|YAP_STRING_ATOM|YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_BIG))
     return TYPE_ERROR_ATOMIC;
-  if (flags & (YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_BIG))
+  if ((flags & (YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_BIG)) == 
+      (YAP_STRING_INT|YAP_STRING_FLOAT|YAP_STRING_BIG))
     return TYPE_ERROR_NUMBER;
-  if (flags & YAP_STRING_ATOM)
+  if (flags & YAP_STRING_ATOM )
     return TYPE_ERROR_ATOM;
   if (flags & YAP_STRING_STRING)
     return TYPE_ERROR_STRING;