diff --git a/CMakeLists.txt b/CMakeLists.txt
index 02f07eab..bab4819e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -939,6 +939,7 @@ CHECK_FUNCTION_EXISTS(getnameinfo VMIME_HAVE_GETNAMEINFO)
 CHECK_FUNCTION_EXISTS(gettid VMIME_HAVE_GETTID)
 CHECK_FUNCTION_EXISTS(syscall VMIME_HAVE_SYSCALL)
 CHECK_SYMBOL_EXISTS(SYS_gettid sys/syscall.h VMIME_HAVE_SYSCALL_GETTID)
+CHECK_SYMBOL_EXISTS(getthrid unistd.h VMIME_HAVE_GETTHRID)
 
 CHECK_SYMBOL_EXISTS(SO_KEEPALIVE sys/socket.h VMIME_HAVE_SO_KEEPALIVE)
 CHECK_SYMBOL_EXISTS(SO_NOSIGPIPE sys/socket.h VMIME_HAVE_SO_NOSIGPIPE)
diff --git a/cmake/config.hpp.cmake b/cmake/config.hpp.cmake
index e87bf9d9..c5e9fdef 100644
--- a/cmake/config.hpp.cmake
+++ b/cmake/config.hpp.cmake
@@ -76,6 +76,7 @@ typedef unsigned @VMIME_64BIT_TYPE@ vmime_uint64;
 #cmakedefine01 VMIME_HAVE_GETTID
 #cmakedefine01 VMIME_HAVE_SYSCALL
 #cmakedefine01 VMIME_HAVE_SYSCALL_GETTID
+#cmakedefine01 VMIME_HAVE_GETTHRID
 #cmakedefine01 VMIME_HAVE_GMTIME_S
 #cmakedefine01 VMIME_HAVE_GMTIME_R
 #cmakedefine01 VMIME_HAVE_LOCALTIME_S
diff --git a/src/vmime/platforms/posix/posixHandler.cpp b/src/vmime/platforms/posix/posixHandler.cpp
index 14877403..e0263b2b 100644
--- a/src/vmime/platforms/posix/posixHandler.cpp
+++ b/src/vmime/platforms/posix/posixHandler.cpp
@@ -260,6 +260,8 @@ unsigned int posixHandler::getThreadId() const
 	return static_cast <unsigned int>(::gettid());
 #elif VMIME_HAVE_SYSCALL && VMIME_HAVE_SYSCALL_GETTID
 	return static_cast <unsigned int>(::syscall(SYS_gettid));
+#elif VMIME_HAVE_GETTHRID  // OpenBSD
+	return static_cast <unsigned int>(::getthrid());
 #else
 	#error We have no implementation of getThreadId() for this platform!
 #endif