diff --git a/lang/cem/cemcom/LLlex.c b/lang/cem/cemcom/LLlex.c
index 9a540f13..3ed953f7 100644
--- a/lang/cem/cemcom/LLlex.c
+++ b/lang/cem/cemcom/LLlex.c
@@ -445,7 +445,7 @@ firstline:
 		buf[0] = '-';	/* good heavens...	*/
 		if (np == &buf[NUMSIZE+1]) {
 			lexerror("floating constant too long");
-			ptok->tk_fval = Salloc("0.0",(unsigned) 5) + 1;
+			ptok->tk_fval = Salloc("-0.0",(unsigned) 5) + 1;
 		}
 		else
 			ptok->tk_fval = Salloc(buf,(unsigned) (np - buf)) + 1;
diff --git a/lang/m2/comp/LLlex.c b/lang/m2/comp/LLlex.c
index 3e0bd954..39b07907 100644
--- a/lang/m2/comp/LLlex.c
+++ b/lang/m2/comp/LLlex.c
@@ -582,7 +582,7 @@ lexwarning(W_ORDINARY, "overflow in constant");
 		PushBack();
 
 		if (np >= &buf[NUMSIZE]) {
-			tk->TOK_REL = Salloc("0.0", 5);
+			tk->TOK_REL = Salloc("-0.0", 5)+1;
 			lexerror("real constant too long");
 		}
 		else	tk->TOK_REL = Salloc(buf, (unsigned) (np - buf)) + 1;