diff --git a/src/chars.c b/src/chars.c
index a842bcbb944dab514b0ed829ea9092930a53bcaa..0f76079e4231c0bb375db262980a4baa98dd96d4 100644
--- a/src/chars.c
+++ b/src/chars.c
@@ -775,7 +775,7 @@ bool has_blank_chars(const char *s)
  * multibyte characters, and FALSE otherwise. */
 bool has_blank_mbchars(const char *s)
 {
-    assert(str != NULL);
+    assert(s != NULL);
 
 #ifdef NANO_WIDE
     if (ISSET(USE_UTF8)) {
diff --git a/src/nano.c b/src/nano.c
index 4fe5a60dbcf802929ce8d374e3ce75cd03497ceb..307e7bd5990f13685f38b3c64abd155d0230715b 100644
--- a/src/nano.c
+++ b/src/nano.c
@@ -2643,7 +2643,7 @@ void justify_format(filestruct *paragraph, size_t skip)
     assert(paragraph != NULL);
     assert(paragraph->data != NULL);
     assert(skip < strlen(paragraph->data));
-    assert(!is_blank_char(paragraph->data[skip]));
+    assert(!isblank(paragraph->data[skip]));
 
     end = paragraph->data + skip;
     new_paragraph_data = charalloc(strlen(paragraph->data) + 1);