diff --git a/asm/preproc.c b/asm/preproc.c
index 0030959e..3fb9e01f 100644
--- a/asm/preproc.c
+++ b/asm/preproc.c
@@ -7076,7 +7076,7 @@ static int expand_mmacro(Token * tline)
      */
     nasm_newn(paramlen, nparam+1);
 
-    for (i = 1; (t = params[i]); i++) {
+    for (i = 1; i < nparam+1 && (t = params[i]); i++) {
         bool braced = false;
         int brace = 0;
         int white = 0;
diff --git a/nasmlib/alloc.c b/nasmlib/alloc.c
index e25e0e0a..df2e02b4 100644
--- a/nasmlib/alloc.c
+++ b/nasmlib/alloc.c
@@ -104,8 +104,10 @@ void *nasm_realloc(void *q, size_t size)
 
 void nasm_free(void *q)
 {
-    if (q)
+    if (q){
         free(q);
+	q = NULL;
+    }
 }
 
 char *nasm_strdup(const char *s)