diff --git a/femtolisp/flisp.c b/femtolisp/flisp.c
index 5938716..1e73d69 100644
--- a/femtolisp/flisp.c
+++ b/femtolisp/flisp.c
@@ -136,7 +136,7 @@ value_t fl_lasterror;
   _ctx.sp=SP; _ctx.frame=curr_frame; _ctx.rdst=readstate; _ctx.prev=fl_ctx; \
   _ctx.ngchnd = N_GCHND; fl_ctx = &_ctx;                                    \
   if (!setjmp(_ctx.buf)) \
-    for (l__tr=1; l__tr; l__tr=0, (void)(fl_ctx->prev&&(fl_ctx=fl_ctx->prev)))
+    for (l__tr=1; l__tr; l__tr=0, (void)(fl_ctx=fl_ctx->prev))
 
 #define FL_CATCH \
   else \
diff --git a/femtolisp/flisp.h b/femtolisp/flisp.h
index e0eff7d..3b1c68e 100644
--- a/femtolisp/flisp.h
+++ b/femtolisp/flisp.h
@@ -179,7 +179,7 @@ extern value_t fl_lasterror;
   fl_exception_context_t _ctx; int l__tr, l__ca;                        \
   fl_savestate(&_ctx); fl_ctx = &_ctx;                                  \
   if (!setjmp(_ctx.buf))                                                \
-    for (l__tr=1; l__tr; l__tr=0, (void)(fl_ctx->prev&&(fl_ctx=fl_ctx->prev)))
+    for (l__tr=1; l__tr; l__tr=0, (void)(fl_ctx=fl_ctx->prev))
 
 #define FL_CATCH_EXTERN \
   else \