diff --git a/libyasm/file.c b/libyasm/file.c
index 10f73fdf..f558695a 100644
--- a/libyasm/file.c
+++ b/libyasm/file.c
@@ -422,7 +422,10 @@ yasm_fopen_include(const char *iname, const char *from, const char *mode,
 	combine = yasm__combpath(from, iname);
 	f = fopen(combine, mode);
 	if (f) {
-	    *oname = combine;
+	    if (oname)
+		*oname = combine;
+	    else
+		yasm_xfree(combine);
 	    return f;
 	}
 	yasm_xfree(combine);
@@ -432,12 +435,17 @@ yasm_fopen_include(const char *iname, const char *from, const char *mode,
 	combine = yasm__combpath(np->path, iname);
 	f = fopen(combine, mode);
 	if (f) {
-	    *oname = combine;
+	    if (oname)
+		*oname = combine;
+	    else
+		yasm_xfree(combine);
 	    return f;
 	}
 	yasm_xfree(combine);
     }
 
+    if (oname)
+	*oname = NULL;
     return NULL;
 }
 
diff --git a/libyasm/file.h b/libyasm/file.h
index f37062d0..d81061d2 100644
--- a/libyasm/file.h
+++ b/libyasm/file.h
@@ -182,12 +182,13 @@ char *yasm__combpath_win(const char *from, const char *to);
  * \param iname	    file to include
  * \param from	    file doing the including
  * \param mode	    fopen mode string
- * \param oname	    full pathname of included file (may be relative)
+ * \param oname	    full pathname of included file (may be relative). NULL
+ *		    may be passed if this is unwanted.
  * \return fopen'ed include file, or NULL if not found.
  */
-/*@null@*/ FILE *yasm_fopen_include(const char *iname, const char *from,
-				    const char *mode,
-				    /*@out@*/ /*@only@*/ char **oname);
+/*@null@*/ FILE *yasm_fopen_include
+    (const char *iname, const char *from, const char *mode,
+     /*@null@*/ /*@out@*/ /*@only@*/ char **oname);
 
 /** Delete any stored include paths added by yasm_add_include_path().
  */