diff --git a/CMakeLists.txt b/CMakeLists.txt
index 31b77bae8cd..772da1456d5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -113,6 +113,14 @@ check_include_file("sys/stat.h" HAVE_SYS_STAT_H)
 check_include_file("sys/types.h" HAVE_SYS_TYPES_H)
 check_include_file("unistd.h" HAVE_UNISTD_H)
 
+# types.h depends on HAVE_LIMITS_H, and it is defined in options.h (rather than
+# config.h) so that applications consuming wolfSSL headers see it. The in-tree
+# build, however, is configured through config.h/compile definitions and does
+# not include options.h, so define it here as well.
+if(HAVE_LIMITS_H)
+    add_definitions("-DHAVE_LIMITS_H")
+endif()
+
 include(CheckFunctionExists)
 
 # TODO: Also check if these functions are declared by the
diff --git a/cmake/config.in b/cmake/config.in
index f2524e41e43..6054b6dbe7b 100644
--- a/cmake/config.in
+++ b/cmake/config.in
@@ -19,9 +19,6 @@
 /* Define to 1 if you have the `gmtime_r' function. */
 #cmakedefine HAVE_GMTIME_R @HAVE_GMTIME_R@
 
-/* Define to 1 if you have the <limits.h> header file. */
-#cmakedefine HAVE_LIMITS_H @HAVE_LIMITS_H@
-
 /* Define to 1 if you have the <pcap/pcap.h> header file. */
 #cmakedefine HAVE_PCAP_PCAP_H @HAVE_PCAP_PCAP_H@
 
diff --git a/cmake/options.h.in b/cmake/options.h.in
index 967fe7b2ad1..dfdee642ca6 100644
--- a/cmake/options.h.in
+++ b/cmake/options.h.in
@@ -38,6 +38,9 @@ extern "C" {
 #undef _POSIX_THREADS
 #cmakedefine _POSIX_THREADS
 #endif
+/* Since types.h depends on HAVE_LIMITS_H, we must define it in options.h. */
+#undef HAVE_LIMITS_H
+#cmakedefine HAVE_LIMITS_H @HAVE_LIMITS_H@
 #undef ASIO_USE_WOLFSSL
 #cmakedefine ASIO_USE_WOLFSSL
 #undef BOOST_ASIO_USE_WOLFSSL
diff --git a/configure.ac b/configure.ac
index 606ed241182..d12f09579a9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -204,7 +204,9 @@ then
     fi
 fi
 
-AC_CHECK_HEADERS([arpa/inet.h fcntl.h limits.h netdb.h netinet/in.h stddef.h time.h sys/ioctl.h sys/socket.h sys/time.h errno.h sys/un.h ctype.h sys/random.h])
+AC_CHECK_HEADERS([arpa/inet.h fcntl.h netdb.h netinet/in.h stddef.h time.h sys/ioctl.h sys/socket.h sys/time.h errno.h sys/un.h ctype.h sys/random.h])
+# Special case: Since types.h depends on HAVE_LIMITS_H, we must define it in options.h.
+AC_CHECK_HEADER([limits.h], [AM_CPPFLAGS="$AM_CPPFLAGS -DHAVE_LIMITS_H=1"], [])
 AC_CHECK_LIB([network],[socket])
 AC_C_BIGENDIAN
 AC_C___ATOMIC
diff --git a/wolfssl/wolfcrypt/types.h b/wolfssl/wolfcrypt/types.h
index cf8900f6ee0..3a1efb79556 100644
--- a/wolfssl/wolfcrypt/types.h
+++ b/wolfssl/wolfcrypt/types.h
@@ -231,6 +231,15 @@ typedef const char wcchar[];
                 (ULONG_MAX == 0xffffffffUL)
             #define SIZEOF_LONG 4
         #endif
+        /* On LP64 (e.g. 64-bit Linux/macOS) long is 8 bytes. Detect it from the
+         * target's own limits.h so CTC_SETTINGS matches the library, which gets
+         * SIZEOF_LONG=8 from config.h. This must be derived per-target (not
+         * baked into options.h), so LLP64 targets such as Windows correctly get
+         * SIZEOF_LONG=4 from the branch above. */
+        #if !defined(SIZEOF_LONG) && defined(ULONG_MAX) && \
+                (ULONG_MAX == 0xffffffffffffffffULL)
+            #define SIZEOF_LONG 8
+        #endif
         #if !defined(SIZEOF_LONG_LONG) && defined(ULLONG_MAX) && \
                 (ULLONG_MAX == 0xffffffffffffffffULL)
             #define SIZEOF_LONG_LONG 8