diff --git a/ChangeLog b/ChangeLog
index 311260e6..a533e01c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -90,6 +90,10 @@ CVS code -
 	  allocated, use null_at() to strip the directory from the
 	  string.  Also, return the stripped path instead of modifying
 	  path. (DLR)
+- chars.c:
+  mbstrncasecmp(), mbstrcasestr(), mbrevstrcasestr()
+	- Don't allocate space for multibyte characters until we've
+	  asserted that the parameters we're using aren't NULL. (DLR)
 - files.c:
   do_insertfile()
 	- If we execute a command in a new buffer, move back to the
diff --git a/src/chars.c b/src/chars.c
index 5f7c3c54..571a5283 100644
--- a/src/chars.c
+++ b/src/chars.c
@@ -527,12 +527,14 @@ int mbstrncasecmp(const char *s1, const char *s2, size_t n)
 {
 #ifdef ENABLE_UTF8
     if (use_utf8) {
-	char *s1_mb = charalloc(MB_CUR_MAX);
-	char *s2_mb = charalloc(MB_CUR_MAX);
+	char *s1_mb, *s2_mb;
 	wchar_t ws1, ws2;
 
 	assert(s1 != NULL && s2 != NULL);
 
+	s1_mb = charalloc(MB_CUR_MAX);
+	s2_mb = charalloc(MB_CUR_MAX);
+
 	while (n > 0 && *s1 != '\0' && *s2 != '\0') {
 	    bool bad_s1_mb = FALSE, bad_s2_mb = FALSE;
 	    int s1_mb_len, s2_mb_len;
@@ -620,13 +622,15 @@ const char *mbstrcasestr(const char *haystack, const char *needle)
 {
 #ifdef ENABLE_UTF8
     if (use_utf8) {
-	char *r_mb = charalloc(MB_CUR_MAX);
-	char *q_mb = charalloc(MB_CUR_MAX);
+	char *r_mb. *q_mb;
 	wchar_t wr, wq;
 	bool found_needle = FALSE;
 
 	assert(haystack != NULL && needle != NULL);
 
+	r_mb = charalloc(MB_CUR_MAX);
+	q_mb = charalloc(MB_CUR_MAX);
+
 	while (*haystack != '\0') {
 	    const char *r = haystack, *q = needle;
 	    int r_mb_len, q_mb_len;
@@ -726,13 +730,15 @@ const char *mbrevstrcasestr(const char *haystack, const char *needle,
 {
 #ifdef ENABLE_UTF8
     if (use_utf8) {
-	char *r_mb = charalloc(MB_CUR_MAX);
-	char *q_mb = charalloc(MB_CUR_MAX);
+	char *r_mb. *q_mb;
 	wchar_t wr, wq;
 	bool begin_line = FALSE, found_needle = FALSE;
 
 	assert(haystack != NULL && needle != NULL && rev_start != NULL);
 
+	r_mb = charalloc(MB_CUR_MAX);
+	q_mb = charalloc(MB_CUR_MAX);
+
 	while (!begin_line) {
 	    const char *r = rev_start, *q = needle;
 	    int r_mb_len, q_mb_len;