diff --git a/common/core.h b/common/core.h
index f3bdb91..ce0b710 100644
--- a/common/core.h
+++ b/common/core.h
@@ -189,11 +189,14 @@ static cell_t parse(cell_t sep, cell_t *ret) {
   return len;
 }
 
-static cell_t *evaluate1(cell_t *sp, float **fp) {
+static cell_t *evaluate1(cell_t *rp) {
   cell_t call = 0;
+  cell_t tos, *sp, *ip;
+  float *fp;
+  UNPARK;
   cell_t name;
   cell_t len = parse(' ', &name);
-  if (len == 0) { *++sp = 0; return sp; }  // ignore empty
+  if (len == 0) { DUP; tos = 0; PARK; return rp; }  // ignore empty
   cell_t xt = find((const char *) name, len);
   if (xt) {
     if (g_sys->state && !(((cell_t *) xt)[-1] & IMMEDIATE)) {
@@ -208,7 +211,7 @@ static cell_t *evaluate1(cell_t *sp, float **fp) {
         *g_sys->heap++ = g_sys->DOLIT_XT;
         *g_sys->heap++ = n;
       } else {
-        *++sp = n;
+        PUSH n;
       }
     } else {
       float f;
@@ -217,7 +220,7 @@ static cell_t *evaluate1(cell_t *sp, float **fp) {
           *g_sys->heap++ = g_sys->DOFLIT_XT;
           *(float *) g_sys->heap++ = f;
         } else {
-          *++(*fp) = f;
+          *++fp = f;
         }
       } else {
 #if PRINT_ERRORS
@@ -225,15 +228,16 @@ static cell_t *evaluate1(cell_t *sp, float **fp) {
         fwrite((void *) name, 1, len, stderr);
         fprintf(stderr, "\n");
 #endif
-        *++sp = name;
-        *++sp = len;
+        PUSH name;
+        PUSH len;
         *++sp = -1;
         call = g_sys->notfound;
       }
     }
   }
-  *++sp = call;
-  return sp;
+  PUSH call;
+  PARK;
+  return rp;
 }
 
 static cell_t *forth_run(cell_t *initrp);
diff --git a/common/opcodes.h b/common/opcodes.h
index ece43b4..8f36648 100644
--- a/common/opcodes.h
+++ b/common/opcodes.h
@@ -140,16 +140,14 @@ typedef struct {
   XV(forth, "CONSTANT", CONSTANT, DUP; DUP; tos = parse(32, sp); \
                         create((const char *) *sp, tos, 0, ADDROF(DOCON)); \
                         DROPn(2); COMMA(tos); DROP) \
-  X("DOES>", DOES, DOES(ip); ip = (cell_t *) *rp; --rp) \
-  Y(IMMEDIATE, DOIMMEDIATE()) \
+  XV(forth, "DOES>", DOES, DOES(ip); ip = (cell_t *) *rp; --rp) \
+  XV(forth, "IMMEDIATE", IMMEDIATE, DOIMMEDIATE()) \
   XV(internals, "'SYS", SYS, DUP; tos = (cell_t) g_sys) \
   YV(internals, YIELD, PARK; return rp) \
   X(":", COLON, DUP; DUP; tos = parse(32, sp); \
                 create((const char *) *sp, tos, SMUDGE, ADDROF(DOCOL)); \
                 g_sys->state = -1; --sp; DROP) \
-  YV(internals, EVALUATE1, DUP; float *tfp = fp; \
-               sp = evaluate1(sp, &tfp); \
-               fp = tfp; w = *sp--; DROP; if (w) JMPW) \
+  YV(internals, EVALUATE1, PARK; rp = evaluate1(rp); UNPARK; w = tos; DROP; if (w) JMPW) \
   Y(EXIT, ip = (cell_t *) *rp--) \
   XV(internals, "'builtins", TBUILTINS, DUP; tos = (cell_t) &g_sys->builtins->code) \
   XV(forth_immediate, ";", SEMICOLON, COMMA(g_sys->DOEXIT_XT); UNSMUDGE(); g_sys->state = 0)
diff --git a/web/fuse_web.js b/web/fuse_web.js
index 68ea16b..5f240ef 100755
--- a/web/fuse_web.js
+++ b/web/fuse_web.js
@@ -88,7 +88,7 @@ cases = ReplaceAll(cases, 'COMMA(tos)', 'COMMA(tos|0)');
 cases = ReplaceAll(cases, /find\(([^\n]+)\);/, 'find($1)|0;');
 cases = ReplaceAll(cases, 'tos = parse(tos, sp)', 'tos = parse(tos|0, sp|0)|0');
 cases = ReplaceAll(cases, 'tos = parse(32, sp)', 'tos = parse(32, sp|0)|0');
-cases = ReplaceAll(cases, 'sp = evaluate1(sp)', 'sp = evaluate1(sp|0)|0');
+cases = ReplaceAll(cases, 'rp = evaluate1(rp)', 'rp = evaluate1(rp|0)|0');
 cases = ReplaceAll(cases, /convert\(([^\n]+), sp\)/, 'convert($1, sp|0)|0');
 cases = ReplaceAll(cases, 'DOES(ip)', 'DOES(ip|0)');
 cases = ReplaceAll(cases, 'PARK;', '');  // TODO