diff --git a/include/tccdefs.h b/include/tccdefs.h
index c32df1b6..7d9017d5 100644
--- a/include/tccdefs.h
+++ b/include/tccdefs.h
@@ -269,7 +269,9 @@
     __BOTH(int, strcmp, (const char*, const char*))
     __BOTH(int, strncmp, (const char*, const char*, __SIZE_TYPE__))
     __BOTH(char*, strcat, (char*, const char*))
+    __BOTH(char*, strncat, (char*, const char*, __SIZE_TYPE__))
     __BOTH(char*, strchr, (const char*, int))
+    __BOTH(char*, strrchr, (const char*, int))
     __BOTH(char*, strdup, (const char*))
 #if defined __ARM_EABI__
     __BOUND(void*,__aeabi_memcpy,(void*,const void*,__SIZE_TYPE__))
diff --git a/lib/bcheck.c b/lib/bcheck.c
index 9216d0f7..0f225869 100644
--- a/lib/bcheck.c
+++ b/lib/bcheck.c
@@ -292,7 +292,9 @@ DLL_EXPORT char *__bound_strncpy(char *dst, const char *src, size_t n);
 DLL_EXPORT int __bound_strcmp(const char *s1, const char *s2);
 DLL_EXPORT int __bound_strncmp(const char *s1, const char *s2, size_t n);
 DLL_EXPORT char *__bound_strcat(char *dest, const char *src);
+DLL_EXPORT char *__bound_strncat(char *dest, const char *src, size_t n);
 DLL_EXPORT char *__bound_strchr(const char *string, int ch);
+DLL_EXPORT char *__bound_strrchr(const char *string, int ch);
 DLL_EXPORT char *__bound_strdup(const char *s);
 
 #if defined(__arm__) && defined(__ARM_EABI__)
@@ -424,7 +426,9 @@ static unsigned long long bound_strncpy_count;
 static unsigned long long bound_strcmp_count;
 static unsigned long long bound_strncmp_count;
 static unsigned long long bound_strcat_count;
+static unsigned long long bound_strncat_count;
 static unsigned long long bound_strchr_count;
+static unsigned long long bound_strrchr_count;
 static unsigned long long bound_strdup_count;
 static unsigned long long bound_not_found;
 #define INCR_COUNT(x)          ++x
@@ -1259,7 +1263,9 @@ void __attribute__((destructor)) __bound_exit(void)
             fprintf (stderr, "bound_strcmp_count       %llu\n", bound_strcmp_count);
             fprintf (stderr, "bound_strncmp_count      %llu\n", bound_strncmp_count);
             fprintf (stderr, "bound_strcat_count       %llu\n", bound_strcat_count);
+            fprintf (stderr, "bound_strncat_count      %llu\n", bound_strncat_count);
             fprintf (stderr, "bound_strchr_count       %llu\n", bound_strchr_count);
+            fprintf (stderr, "bound_strrchr_count      %llu\n", bound_strrchr_count);
             fprintf (stderr, "bound_strdup_count       %llu\n", bound_strdup_count);
             fprintf (stderr, "bound_not_found          %llu\n", bound_not_found);
 #endif
@@ -1940,6 +1946,24 @@ char *__bound_strcat(char *dest, const char *src)
     return strcat(r, s);
 }
 
+char *__bound_strncat(char *dest, const char *src, size_t n)
+{
+    char *r = dest;
+    const char *s = src;
+    size_t len = n;
+
+    dprintf(stderr, "%s, %s(): %p, %p, 0x%lx\n",
+            __FILE__, __FUNCTION__, dest, src, (unsigned long)n);
+    INCR_COUNT(bound_strncat_count);
+    while (*dest++);
+    while (len-- && *src++);
+    __bound_check(r, (dest - r) + (src - s) - 1, "strncat dest");
+    __bound_check(s, src - s, "strncat src");
+    if (check_overlap(r, (dest - r) + (src - s) - 1, s, src - s, "strncat"))
+        return dest;
+    return strncat(r, s, n);
+}
+
 char *__bound_strchr(const char *s, int c)
 {
     const unsigned char *str = (const unsigned char *) s;
@@ -1957,6 +1981,24 @@ char *__bound_strchr(const char *s, int c)
     return *str == ch ? (char *) str : NULL;
 }
 
+char *__bound_strrchr(const char *s, int c)
+{
+    const unsigned char *str = (const unsigned char *) s;
+    unsigned char ch = c;
+
+    dprintf(stderr, "%s, %s(): %p, %d\n",
+            __FILE__, __FUNCTION__, s, ch);
+    INCR_COUNT(bound_strrchr_count);
+    while (*str++);
+    __bound_check(s, (const char *)str - s, "strrchr");
+    while (str != (const unsigned char *)s) {
+        if (*--str == ch)
+            break;
+    }
+    __bound_check(s, (const char *)str - s, "strrchr");
+    return *str == ch ? (char *) str : NULL;
+}
+
 char *__bound_strdup(const char *s)
 {
     const char *p = s;
diff --git a/tests/tests2/112_backtrace.c b/tests/tests2/112_backtrace.c
index 8489bd32..0b596d08 100644
--- a/tests/tests2/112_backtrace.c
+++ b/tests/tests2/112_backtrace.c
@@ -156,8 +156,18 @@ int main()
 #elif defined test_bcheck_125
     strcat(&a[3], &a[0]);
 #elif defined test_bcheck_126
-    strchr(&b[0], 'a');
+    strncat(&a[7], &a[0], 3);
 #elif defined test_bcheck_127
+    strncat(&a[0], &b[3], 8);
+#elif defined test_bcheck_128
+    strncat(&a[0], &a[4], 3);
+#elif defined test_bcheck_129
+    strncat(&a[3], &a[0], 10);
+#elif defined test_bcheck_130
+    strchr(&b[0], 'a');
+#elif defined test_bcheck_131
+    strrchr(&b[0], 'a');
+#elif defined test_bcheck_132
     free(strdup(&b[0]));
 #endif
 }
diff --git a/tests/tests2/112_backtrace.expect b/tests/tests2/112_backtrace.expect
index 68986c6e..ec2c6b8e 100644
--- a/tests/tests2/112_backtrace.expect
+++ b/tests/tests2/112_backtrace.expect
@@ -134,9 +134,29 @@
 [returns 255]
 
 [test_bcheck_126]
-112_backtrace.c:159: at main: BCHECK: invalid pointer ........, size 0x? in strchr
+112_backtrace.c:159: at main: BCHECK: invalid pointer ........, size 0x? in strncat dest
 [returns 255]
 
 [test_bcheck_127]
-112_backtrace.c:161: at main: BCHECK: invalid pointer ........, size 0x? in strdup
+112_backtrace.c:161: at main: BCHECK: invalid pointer ........, size 0x? in strncat dest
+[returns 255]
+
+[test_bcheck_128]
+112_backtrace.c:163: at main: BCHECK: overlapping regions ........(0x?), ........(0x?) in strncat
+[returns 255]
+
+[test_bcheck_129]
+112_backtrace.c:165: at main: BCHECK: overlapping regions ........(0x?), ........(0x?) in strncat
+[returns 255]
+
+[test_bcheck_130]
+112_backtrace.c:167: at main: BCHECK: invalid pointer ........, size 0x? in strchr
+[returns 255]
+
+[test_bcheck_131]
+112_backtrace.c:169: at main: BCHECK: invalid pointer ........, size 0x? in strrchr
+[returns 255]
+
+[test_bcheck_132]
+112_backtrace.c:171: at main: BCHECK: invalid pointer ........, size 0x? in strdup
 [returns 255]
diff --git a/tests/tests2/117_builtins.c b/tests/tests2/117_builtins.c
index 4da28ff5..4c6ffd4b 100644
--- a/tests/tests2/117_builtins.c
+++ b/tests/tests2/117_builtins.c
@@ -60,12 +60,20 @@ main (void)
   r = (__builtin_memcmp (p, str, sizeof(str)));
   printf(" 11:%d", !r);
 
-  r = (__builtin_strchr(p, 'z') != &p[25]);
+  tmp[0] = '\0';
+  p = __builtin_strncat(tmp, str, __builtin_strlen(str));
+  r = (__builtin_memcmp (p, str, sizeof(str)));
   printf(" 12:%d", !r);
 
+  r = (__builtin_strchr(p, 'z') != &p[25]);
+  printf(" 13:%d", !r);
+
+  r = (__builtin_strrchr(p, 'z') != &p[25]);
+  printf(" 14:%d", !r);
+
   p = __builtin_strdup (str);
   r = (__builtin_memcmp (p, str, sizeof(str)));
-  printf(" 13:%d", !r);
+  printf(" 15:%d", !r);
   __builtin_free(p);
 
   p = __builtin_malloc (100);
diff --git a/tests/tests2/117_builtins.expect b/tests/tests2/117_builtins.expect
index 776e4329..f2c78ba7 100644
--- a/tests/tests2/117_builtins.expect
+++ b/tests/tests2/117_builtins.expect
@@ -1,4 +1,4 @@
 BOUNDS OFF:
- 1:1 2:1 3:1 4:1 5:1 6:1 7:1 8:1 9:1 10:1 11:1 12:1 13:1
+ 1:1 2:1 3:1 4:1 5:1 6:1 7:1 8:1 9:1 10:1 11:1 12:1 13:1 14:1 15:1
 BOUNDS ON:
- 1:1 2:1 3:1 4:1 5:1 6:1 7:1 8:1 9:1 10:1 11:1 12:1 13:1
+ 1:1 2:1 3:1 4:1 5:1 6:1 7:1 8:1 9:1 10:1 11:1 12:1 13:1 14:1 15:1