diff --git a/libstdc++-v3/include/bits/regex.h b/libstdc++-v3/include/bits/regex.h
index bf02bff7c49..3c44bcd7e33 100644
--- a/libstdc++-v3/include/bits/regex.h
+++ b/libstdc++-v3/include/bits/regex.h
@@ -467,7 +467,10 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
        */
       basic_regex(const _Ch_type* __p, std::size_t __len,
 		  flag_type __f = ECMAScript)
-      { _M_compile(__p, __p + __len, __f); }
+      {
+	__glibcxx_requires_string_len(__p, __len);
+	_M_compile(__p, __p + __len, __f);
+      }
 
       /**
        * @brief Copy-constructs a basic regular expression.
@@ -684,6 +687,7 @@ _GLIBCXX_BEGIN_NAMESPACE_CXX11
 	  if constexpr (__detail::__is_contiguous_iter<_InputIterator>::value
 			&& is_same_v<_ValT, value_type>)
 	    {
+	      __glibcxx_requires_valid_range(__first, __last);
 	      const auto __len = __last - __first;
 	      const _Ch_type* __p = std::__to_address(__first);
 	      _M_compile(__p, __p + __len, __flags);
diff --git a/libstdc++-v3/include/bits/regex_scanner.tcc b/libstdc++-v3/include/bits/regex_scanner.tcc
index d81627dc3e9..2fa2303f27b 100644
--- a/libstdc++-v3/include/bits/regex_scanner.tcc
+++ b/libstdc++-v3/include/bits/regex_scanner.tcc
@@ -83,7 +83,7 @@ namespace __detail
 	_M_scan_in_brace();
       else
 	{
-	  __glibcxx_assert(false);
+	  __glibcxx_assert(!"unexpected state while processing regex");
 	}
     }
 
@@ -195,7 +195,7 @@ namespace __detail
 		_M_token = __it->second;
 		return;
 	      }
-	  __glibcxx_assert(false);
+	  __glibcxx_assert(!"unexpected special character in regex");
 	}
       else
 	{