diff --git a/lib/atoi/strtou_noneg.c b/lib/atoi/strtou_noneg.c
index ec8773d7..96a0b530 100644
--- a/lib/atoi/strtou_noneg.c
+++ b/lib/atoi/strtou_noneg.c
@@ -14,5 +14,3 @@ extern inline uintmax_t strtou_noneg(const char *s, char **restrict endp,
 
 extern inline unsigned long strtoul_noneg(const char *s,
     char **restrict endp, int base);
-extern inline unsigned long long strtoull_noneg(const char *s,
-    char **restrict endp, int base);
diff --git a/lib/atoi/strtou_noneg.h b/lib/atoi/strtou_noneg.h
index a1d15569..c9411d0e 100644
--- a/lib/atoi/strtou_noneg.h
+++ b/lib/atoi/strtou_noneg.h
@@ -23,9 +23,6 @@ inline uintmax_t strtou_noneg(const char *s, char **restrict endp,
 ATTR_STRING(1) ATTR_ACCESS(write_only, 2)
 inline unsigned long strtoul_noneg(const char *s,
     char **restrict endp, int base);
-ATTR_STRING(1) ATTR_ACCESS(write_only, 2)
-inline unsigned long long strtoull_noneg(const char *s,
-    char **restrict endp, int base);
 
 
 inline uintmax_t
@@ -54,15 +51,4 @@ strtoul_noneg(const char *s, char **restrict endp, int base)
 }
 
 
-inline unsigned long long
-strtoull_noneg(const char *s, char **restrict endp, int base)
-{
-	if (strtol(s, endp, base) < 0) {
-		errno = ERANGE;
-		return 0;
-	}
-	return strtoull(s, endp, base);
-}
-
-
 #endif  // include guard
diff --git a/tests/unit/test_atoi_strtou_noneg.c b/tests/unit/test_atoi_strtou_noneg.c
index 978bc0c4..60631210 100644
--- a/tests/unit/test_atoi_strtou_noneg.c
+++ b/tests/unit/test_atoi_strtou_noneg.c
@@ -17,7 +17,6 @@
 
 
 static void test_strtoul_noneg(void **state);
-static void test_strtoull_noneg(void **state);
 
 
 int
@@ -25,7 +24,6 @@ main(void)
 {
     const struct CMUnitTest  tests[] = {
         cmocka_unit_test(test_strtoul_noneg),
-        cmocka_unit_test(test_strtoull_noneg),
     };
 
     return cmocka_run_group_tests(tests, NULL, NULL);
@@ -52,25 +50,3 @@ test_strtoul_noneg(void **state)
 	assert_true(strtoul_noneg("-0x10000000000000000", NULL, 0) == 0);
 	assert_true(errno == ERANGE);
 }
-
-
-static void
-test_strtoull_noneg(void **state)
-{
-	errno = 0;
-	assert_true(strtoull_noneg("42", NULL, 0) == 42);
-	assert_true(errno == 0);
-
-	assert_true(strtoull_noneg("-1", NULL, 0) == 0);
-	assert_true(errno == ERANGE);
-	errno = 0;
-	assert_true(strtoull_noneg("-3", NULL, 0) == 0);
-	assert_true(errno == ERANGE);
-	errno = 0;
-	assert_true(strtoull_noneg("-0xFFFFFFFFFFFFFFFF", NULL, 0) == 0);
-	assert_true(errno == ERANGE);
-
-	errno = 0;
-	assert_true(strtoull_noneg("-0x10000000000000000", NULL, 0) == 0);
-	assert_true(errno == ERANGE);
-}