diff --git a/src/spicelib/parser/inpptree-parser.y b/src/spicelib/parser/inpptree-parser.y
index 626598537..c83c95e66 100644
--- a/src/spicelib/parser/inpptree-parser.y
+++ b/src/spicelib/parser/inpptree-parser.y
@@ -1,6 +1,6 @@
 %{
     /*
-     * (compile (concat "bison " buffer-file-name))
+     * (compile (concat "bison " (file-relative-name buffer-file-name)))
      */
 
   #include <stdio.h>
@@ -94,7 +94,7 @@ expression: exp
 
 exp:
     TOK_NUM                           { $$ = mknnode($1); }
-  | TOK_STR                           { $$ = mksnode($1, ckt); }
+  | TOK_STR                           { $$ = mksnode($1, ckt); txfree((void*)$1); }
 
   | exp '+' exp                       { $$ = mkbnode("+", $1, $3); }
   | exp '-' exp                       { $$ = mkbnode("-", $1, $3); }
@@ -106,7 +106,7 @@ exp:
 
   | '-' exp  %prec NEG                { $$ = mkfnode("-",$2); }
 
-  | TOK_STR '(' nonempty_arglist ')'  { $$ = mkfnode($1, $3); }
+  | TOK_STR '(' nonempty_arglist ')'  { $$ = mkfnode($1, $3); txfree((void*)$1); }
 
   | TOK_pnode
 
diff --git a/src/spicelib/parser/inpptree.c b/src/spicelib/parser/inpptree.c
index 9c57f3d43..7e3686f8e 100644
--- a/src/spicelib/parser/inpptree.c
+++ b/src/spicelib/parser/inpptree.c
@@ -1021,7 +1021,7 @@ static INPparseNode *mksnode(const char *string, void *ckt)
     if (i == NUM_CONSTANTS) {
 	/* We'd better save this in case it's part of i(something). */
 	p->type = PT_PLACEHOLDER;
-	p->funcname = (/*nonconst*/ char *) string;
+	p->funcname = copy(string);
     } else {
 	p->type = PT_CONSTANT;
 	p->constant = constants[i].value;