diff --git a/include/stringzilla/stringzilla.hpp b/include/stringzilla/stringzilla.hpp
index 49644eca..08b89a7d 100644
--- a/include/stringzilla/stringzilla.hpp
+++ b/include/stringzilla/stringzilla.hpp
@@ -2656,7 +2656,8 @@ class basic_string_slice {
      *  @return For an @b empty `other`, `min(until, size())`.
      */
     size_type rfind(string_view other, size_type until) const noexcept(false) {
-        return until + other.size() < length_ ? substr(0, until + other.size()).rfind(other) : rfind(other);
+        return other.size() < length_ && until < length_ - other.size() ? substr(0, until + other.size()).rfind(other)
+                                                                        : rfind(other);
     }
 
     /**
@@ -2775,7 +2776,7 @@ class basic_string_slice {
      *  @param until The offset of the last character to be considered.
      */
     size_type find_last_of(byteset set, size_type until) const noexcept {
-        auto len = sz_min_of_two(until + 1, length_);
+        auto len = until < length_ ? until + 1 : length_;
         auto ptr = sz_rfind_byteset(start_, len, &set.raw());
         return ptr ? ptr - start_ : npos;
     }
diff --git a/test/find.cpp b/test/find.cpp
index 8ccdcff3..b5eec031 100644
--- a/test/find.cpp
+++ b/test/find.cpp
@@ -161,15 +161,6 @@ static void check_find_unit_(                      //
 void test_find_unit() {
     std::printf("  - testing search & comparison known-answer vectors...\n");
 
-    // Default views use a null pointer, which must not turn an empty match into npos.
-    for (sz::string_view empty : {sz::string_view(), sz::string_view("")}) {
-        verify(empty.find("") == 0);
-        verify(empty.rfind("") == 0);
-        verify(empty.rfind("", sz::string_view::npos) == 0);
-        verify(empty.contains(""));
-        verify(empty.find("a") == sz::string_view::npos);
-    }
-
     char const *hello = "hello world";
     sz_size_t const hello_length = (sz_size_t)std::strlen(hello); // 11 bytes
 
diff --git a/test/string.cpp b/test/string.cpp
index bc839f0c..57e3075e 100644
--- a/test/string.cpp
+++ b/test/string.cpp
@@ -835,6 +835,8 @@ void test_stl_reads_unit() {
     verify(str("hello").rfind('l', 1) == str::npos);
 
     // Substring search in normal and reverse directions.
+    verify(str().find("") == 0);
+    verify(str().rfind("") == 0);
     verify(str("hello").find("ell") == 1);
     verify(str("hello").find("ell", 1) == 1);
     verify(str("hello").find("ell", 2) == str::npos);
@@ -938,6 +940,9 @@ void test_stl_reads_unit() {
     }
 
     // Boundary conditions.
+    auto const max_pos = std::numeric_limits<std::size_t>::max();
+    verify(str("hello").rfind("ell", max_pos) == 1);
+    verify(str("hello").find_last_of("le", max_pos) == 3);
     verify(str("hello").find_first_of("ox", 4) == 4);
     verify(str("hello").find_first_of("ox", 5) == str::npos);
     verify(str("hello").find_last_of("ox", 4) == 4);