diff --git a/js/src/jsparse.c b/js/src/jsparse.c
index 656afc2f0a2b..f0679dd3c6ac 100644
--- a/js/src/jsparse.c
+++ b/js/src/jsparse.c
@@ -1106,7 +1106,7 @@ MatchLabel(JSContext *cx, JSTokenStream *ts, JSParseNode *pn)
     label = NULL;
 #endif
     pn->pn_atom = label;
-    if (pn->pn_pos.end.lineno == ts->lineno)
+    if (ON_CURRENT_LINE(ts, pn->pn_pos))
         return WellTerminated(cx, ts, TOK_ERROR);
     return JS_TRUE;
 }
@@ -1246,7 +1246,7 @@ Statement(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
             } while (js_MatchToken(cx, ts, TOK_COMMA));
         }
         pn->pn_pos.end = PN_LAST(pn)->pn_pos.end;
-        if (pn->pn_pos.end.lineno == ts->lineno &&
+        if (ON_CURRENT_LINE(ts, pn->pn_pos) &&
             !WellTerminated(cx, ts, TOK_ERROR)) {
             return NULL;
         }
@@ -1265,7 +1265,7 @@ Statement(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
             PN_APPEND(pn, pn2);
         } while (js_MatchToken(cx, ts, TOK_COMMA));
         pn->pn_pos.end = PN_LAST(pn)->pn_pos.end;
-        if (pn->pn_pos.end.lineno == ts->lineno &&
+        if (ON_CURRENT_LINE(ts, pn->pn_pos) &&
             !WellTerminated(cx, ts, TOK_ERROR)) {
             return NULL;
         }
@@ -1277,7 +1277,7 @@ Statement(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
         pn = FunctionStmt(cx, ts, tc);
         if (!pn)
             return NULL;
-        if (pn->pn_pos.end.lineno == ts->lineno &&
+        if (ON_CURRENT_LINE(ts, pn->pn_pos) &&
             !WellTerminated(cx, ts, TOK_FUNCTION)) {
             return NULL;
         }
@@ -1693,7 +1693,7 @@ Statement(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
         if (!pn2)
             return NULL;
         pn->pn_pos.end = pn2->pn_pos.end;
-        if (pn->pn_pos.end.lineno == ts->lineno &&
+        if (ON_CURRENT_LINE(ts, pn->pn_pos) &&
             !WellTerminated(cx, ts, TOK_ERROR)) {
             return NULL;
         }
@@ -1825,7 +1825,7 @@ Statement(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
         pn = Variables(cx, ts, tc);
         if (!pn)
             return NULL;
-        if (pn->pn_pos.end.lineno == ts->lineno &&
+        if (ON_CURRENT_LINE(ts, pn->pn_pos) &&
             !WellTerminated(cx, ts, TOK_ERROR)) {
             return NULL;
         }
@@ -1854,7 +1854,7 @@ Statement(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
             pn2 = Expr(cx, ts, tc);
             if (!pn2)
                 return NULL;
-            if (pn2->pn_pos.end.lineno == ts->lineno &&
+            if (ON_CURRENT_LINE(ts, pn2->pn_pos) &&
                 !WellTerminated(cx, ts, TOK_ERROR)) {
                 return NULL;
             }
@@ -1950,7 +1950,7 @@ Statement(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
         }
 
         /* Check termination of (possibly multi-line) function expression. */
-        if (pn2->pn_pos.end.lineno == ts->lineno &&
+        if (ON_CURRENT_LINE(ts, pn2->pn_pos) &&
             !WellTerminated(cx, ts, lastExprType)) {
             return NULL;
         }
@@ -2626,7 +2626,7 @@ UnaryExpr(JSContext *cx, JSTokenStream *ts, JSTreeContext *tc)
             return NULL;
 
         /* Don't look across a newline boundary for a postfix incop. */
-        if (pn->pn_pos.end.lineno == ts->lineno) {
+        if (ON_CURRENT_LINE(ts, pn->pn_pos)) {
             tt = js_PeekTokenSameLine(cx, ts);
             if (tt == TOK_INC || tt == TOK_DEC) {
                 (void) js_GetToken(cx, ts);
diff --git a/js/src/jsscan.c b/js/src/jsscan.c
index f25e02a42337..e0bc5cd92747 100644
--- a/js/src/jsscan.c
+++ b/js/src/jsscan.c
@@ -656,7 +656,7 @@ js_PeekTokenSameLine(JSContext *cx, JSTokenStream *ts)
     JSTokenType tt;
 
     JS_ASSERT(ts->lookahead == 0 ||
-              CURRENT_TOKEN(ts).pos.end.lineno == ts->lineno);
+              ON_CURRENT_LINE(ts, CURRENT_TOKEN(ts).pos));
     ts->flags |= TSF_NEWLINES;
     tt = js_PeekToken(cx, ts);
     ts->flags &= ~TSF_NEWLINES;
@@ -775,7 +775,7 @@ retry:
     tp = &CURRENT_TOKEN(ts);
     tp->ptr = ts->linebuf.ptr - 1;
     tp->pos.begin.index = ts->linepos + (tp->ptr - ts->linebuf.base);
-    tp->pos.begin.lineno = tp->pos.end.lineno = ts->lineno;
+    tp->pos.begin.lineno = tp->pos.end.lineno = (uint16)ts->lineno;
 
     if (c == EOF)
         RETURN(TOK_EOF);
@@ -994,7 +994,7 @@ retry:
                                0);
         if (!atom)
             RETURN(TOK_ERROR);
-        tp->pos.end.lineno = ts->lineno;
+        tp->pos.end.lineno = (uint16)ts->lineno;
         tp->t_op = JSOP_STRING;
         tp->t_atom = atom;
         RETURN(TOK_STRING);
diff --git a/js/src/jsscan.h b/js/src/jsscan.h
index 430349c8e48b..c61eff926d65 100644
--- a/js/src/jsscan.h
+++ b/js/src/jsscan.h
@@ -173,7 +173,8 @@ struct JSTokenStream {
     void                *listenerTSData;/* listener data for this TokenStream */
 };
 
-#define CURRENT_TOKEN(ts) ((ts)->tokens[(ts)->cursor])
+#define CURRENT_TOKEN(ts)       ((ts)->tokens[(ts)->cursor])
+#define ON_CURRENT_LINE(ts,pos) ((uint16)(ts)->lineno == (pos).end.lineno)
 
 /* JSTokenStream flags */
 #define TSF_ERROR       0x01            /* fatal error while compiling */