diff --git a/CMakeLists.txt b/CMakeLists.txt
index 45d8c413..e2e1f578 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -65,7 +65,7 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Linux" OR CMAKE_SYSTEM_NAME MATCHES "GNU|kFreeBSD
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS}  -Wno-reorder -Wno-unused-but-set-variable -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-unused-function -Wno-format")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}  -Wno-reorder -Wno-unused-but-set-variable -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-unused-function -Wno-format")
 endif()
-if(CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
+if(CMAKE_SYSTEM_NAME STREQUAL "FreeBSD" OR CMAKE_SYSTEM_NAME STREQUAL "OpenBSD")
     SET(FREEBSD TRUE)
 endif()
 if(APPLE)
diff --git a/README.md b/README.md
index c2838444..9a3fa2ba 100644
--- a/README.md
+++ b/README.md
@@ -127,6 +127,49 @@ make -j4
 make install
 ```
 
+### OpenBSD
+
+#### Install the required packages
+```
+sudo pkg_add bison cmake git sdl2 libogg libvorbis nasm
+```
+#### Setting up the repository
+
+```
+git clone https://github.com/tx00100xt/SeriousSamClassic.git
+```
+
+#### Copy official game data (optional)
+
+If you have access to a copy of the game (either by CD or through Steam),
+you can copy the *.gro files from the game directory to the repository.
+(SeriousSamClassic/SamTFE is the directory of the game Serious Sam Classic The First Encounter, SeriousSamClassic/SamTSE is the directory of the game Serious Sam Classic The Second Encounter)
+
+#### Building for amd64 (for SS:TFE and SS:TSE)
+
+Type this in your terminal:
+
+```
+cd SeriousSamClassic
+mkdir build
+cd build
+cmake ..
+make -j4
+make install
+```
+#### Building for i386 (for SS:TFE and SS:TSE)
+
+Type this in your terminal:
+
+```
+cd SeriousSamClassic
+mkdir build
+cd build
+cmake .. -DCMAKE_C_FLAGS=-mmmx -DCMAKE_CXX_FLAGS=-mmmx -DCMAKE_SHARED_LINKER_FLAGS='-Wl,-znotext' -DUSE_I386_NASM_ASM=TRUE
+make -j4
+make install
+```
+
 ### macOS
 
 #### Install dependes
@@ -321,6 +364,7 @@ Supported OS
 -----------
 * `Linux`
 * `FreeBSD`
+* `OpenBSD`
 * `Windows`
 * `Raspberry PI OS`
 * `macOS`
diff --git a/SamTFE/Sources/Engine/Base/Base.h b/SamTFE/Sources/Engine/Base/Base.h
index 0f021cf0..64793342 100644
--- a/SamTFE/Sources/Engine/Base/Base.h
+++ b/SamTFE/Sources/Engine/Base/Base.h
@@ -64,6 +64,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
     #define PLATFORM_MACOSX 1
 #elif (defined __FreeBSD__)
     #define PLATFORM_FREEBSD 1
+#elif (defined __OpenBSD__)
+    #define PLATFORM_OPENBSD 1
+    #define PLATFORM_FREEBSD 1
 #else
   #warning "UNKNOWN PLATFORM IDENTIFIED!!!!"
   #define PLATFORM_UNKNOWN 1
diff --git a/SamTFE/Sources/Engine/Base/ListIterator.inl b/SamTFE/Sources/Engine/Base/ListIterator.inl
index 5c3f1b05..ec91cb15 100644
--- a/SamTFE/Sources/Engine/Base/ListIterator.inl
+++ b/SamTFE/Sources/Engine/Base/ListIterator.inl
@@ -79,6 +79,12 @@ public:
    iter##next=iter, iter##next.IsPastEnd() || (iter##next.MoveToNext(),1), !iter.IsPastEnd(); \
      iter = iter##next)
 
+#ifdef PLATFORM_OPENBSD
+#ifdef LIST_HEAD
+  #undef LIST_HEAD
+#endif
+#endif
+
 // get the pointer to the first element in the list
 #define LIST_HEAD(listhead, baseclass, member) \
   ( (baseclass *) ( ((UBYTE *)(&(listhead).Head())) - _offsetof(baseclass, member) ) )
diff --git a/SamTFE/Sources/Engine/Engine.h b/SamTFE/Sources/Engine/Engine.h
index 176bf06a..8307f703 100644
--- a/SamTFE/Sources/Engine/Engine.h
+++ b/SamTFE/Sources/Engine/Engine.h
@@ -32,8 +32,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include <stdlib.h>
 #if (!defined __INTEL_COMPILER) && (!defined PLATFORM_MACOSX)
+#ifdef PLATFORM_OPENBSD
+#include <sys/malloc.h>
+#else
 #include <malloc.h>
 #endif
+#endif
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/SamTFE/Sources/Engine/Templates/LinearAllocator.cpp b/SamTFE/Sources/Engine/Templates/LinearAllocator.cpp
index 418f53bb..f9b6b319 100644
--- a/SamTFE/Sources/Engine/Templates/LinearAllocator.cpp
+++ b/SamTFE/Sources/Engine/Templates/LinearAllocator.cpp
@@ -148,6 +148,15 @@ inline void CLinearAllocator<Type>::Reset(void)
     // do nothing
     return;
 
+#ifdef PLATFORM_OPENBSD
+#ifdef LIST_HEAD
+  #undef LIST_HEAD
+#endif
+// get the pointer to the first element in the list
+#define LIST_HEAD(listhead, baseclass, member) \
+  ( (baseclass *) ( ((UBYTE *)(&(listhead).Head())) - _offsetof(baseclass, member) ) )
+#endif
+
   // if there is only one block allocated
   } else if (&la_lhBlocks.Head()==&la_lhBlocks.Tail()) {
     // just restart at the beginning
diff --git a/SamTFE/Sources/GameMP/Game.cpp b/SamTFE/Sources/GameMP/Game.cpp
index 8b4cc7a5..a8f36228 100644
--- a/SamTFE/Sources/GameMP/Game.cpp
+++ b/SamTFE/Sources/GameMP/Game.cpp
@@ -18,7 +18,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "StdAfx.h"
 #include "GameMP/Game.h"
+#ifndef PLATFORM_OPENBSD
 #include <sys/timeb.h>
+#endif
 #include <time.h>
 #include <locale.h>
 
diff --git a/SamTFE/Sources/SeriousSam/Menu.cpp b/SamTFE/Sources/SeriousSam/Menu.cpp
index 86bb9f32..7503287c 100644
--- a/SamTFE/Sources/SeriousSam/Menu.cpp
+++ b/SamTFE/Sources/SeriousSam/Menu.cpp
@@ -2,7 +2,9 @@
 
 #include "SeriousSam/StdH.h"
 #include <Engine/Build.h>
+#ifndef PLATFORM_OPENBSD
 #include <sys/timeb.h>
+#endif
 #include <time.h>
 
 #ifdef PLATFORM_WIN32
diff --git a/SamTSE/Sources/Engine/Base/Base.h b/SamTSE/Sources/Engine/Base/Base.h
index 0f021cf0..64793342 100644
--- a/SamTSE/Sources/Engine/Base/Base.h
+++ b/SamTSE/Sources/Engine/Base/Base.h
@@ -64,6 +64,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
     #define PLATFORM_MACOSX 1
 #elif (defined __FreeBSD__)
     #define PLATFORM_FREEBSD 1
+#elif (defined __OpenBSD__)
+    #define PLATFORM_OPENBSD 1
+    #define PLATFORM_FREEBSD 1
 #else
   #warning "UNKNOWN PLATFORM IDENTIFIED!!!!"
   #define PLATFORM_UNKNOWN 1
diff --git a/SamTSE/Sources/Engine/Base/ListIterator.inl b/SamTSE/Sources/Engine/Base/ListIterator.inl
index 5c3f1b05..ec91cb15 100644
--- a/SamTSE/Sources/Engine/Base/ListIterator.inl
+++ b/SamTSE/Sources/Engine/Base/ListIterator.inl
@@ -79,6 +79,12 @@ public:
    iter##next=iter, iter##next.IsPastEnd() || (iter##next.MoveToNext(),1), !iter.IsPastEnd(); \
      iter = iter##next)
 
+#ifdef PLATFORM_OPENBSD
+#ifdef LIST_HEAD
+  #undef LIST_HEAD
+#endif
+#endif
+
 // get the pointer to the first element in the list
 #define LIST_HEAD(listhead, baseclass, member) \
   ( (baseclass *) ( ((UBYTE *)(&(listhead).Head())) - _offsetof(baseclass, member) ) )
diff --git a/SamTSE/Sources/Engine/Engine.h b/SamTSE/Sources/Engine/Engine.h
index 176bf06a..8307f703 100644
--- a/SamTSE/Sources/Engine/Engine.h
+++ b/SamTSE/Sources/Engine/Engine.h
@@ -32,8 +32,12 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include <stdlib.h>
 #if (!defined __INTEL_COMPILER) && (!defined PLATFORM_MACOSX)
+#ifdef PLATFORM_OPENBSD
+#include <sys/malloc.h>
+#else
 #include <malloc.h>
 #endif
+#endif
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/SamTSE/Sources/Engine/Templates/LinearAllocator.cpp b/SamTSE/Sources/Engine/Templates/LinearAllocator.cpp
index 418f53bb..f9b6b319 100644
--- a/SamTSE/Sources/Engine/Templates/LinearAllocator.cpp
+++ b/SamTSE/Sources/Engine/Templates/LinearAllocator.cpp
@@ -148,6 +148,15 @@ inline void CLinearAllocator<Type>::Reset(void)
     // do nothing
     return;
 
+#ifdef PLATFORM_OPENBSD
+#ifdef LIST_HEAD
+  #undef LIST_HEAD
+#endif
+// get the pointer to the first element in the list
+#define LIST_HEAD(listhead, baseclass, member) \
+  ( (baseclass *) ( ((UBYTE *)(&(listhead).Head())) - _offsetof(baseclass, member) ) )
+#endif
+
   // if there is only one block allocated
   } else if (&la_lhBlocks.Head()==&la_lhBlocks.Tail()) {
     // just restart at the beginning
diff --git a/SamTSE/Sources/GameMP/Game.cpp b/SamTSE/Sources/GameMP/Game.cpp
index f5b0fcb6..e8b36c9d 100644
--- a/SamTSE/Sources/GameMP/Game.cpp
+++ b/SamTSE/Sources/GameMP/Game.cpp
@@ -18,7 +18,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "StdAfx.h"
 #include "GameMP/Game.h"
+#ifndef PLATFORM_OPENBSD
 #include <sys/timeb.h>
+#endif
 #include <time.h>
 #include <locale.h>
 
diff --git a/SamTSE/Sources/SeriousSam/Menu.cpp b/SamTSE/Sources/SeriousSam/Menu.cpp
index 86bb9f32..7503287c 100644
--- a/SamTSE/Sources/SeriousSam/Menu.cpp
+++ b/SamTSE/Sources/SeriousSam/Menu.cpp
@@ -2,7 +2,9 @@
 
 #include "SeriousSam/StdH.h"
 #include <Engine/Build.h>
+#ifndef PLATFORM_OPENBSD
 #include <sys/timeb.h>
+#endif
 #include <time.h>
 
 #ifdef PLATFORM_WIN32