diff --git a/CMakeLists.txt b/CMakeLists.txt
index 419c7abd9be..e2b71d974ae 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -49,6 +49,20 @@ if( ${TARGET_OS} STREQUAL "Linux" )
     message("Unsupported architecture: ${TARGET_ARCHITECTURE}" )
     return()
   endif()
+elseif( ${TARGET_OS} STREQUAL "OpenBSD")
+  set(OS "OPENBSD")
+  set(OSNAME "OpenBSD")
+  if ( ${TARGET_ARCHITECTURE} STREQUAL "amd64" )
+    set(ARCHNAME x86-64)
+    set(ARCH X86)
+    set(WRDSZ 64)
+    set(TARGET_ARCHITECTURE x86_64)
+  elseif( ${TARGET_ARCHITECTURE} STREQUAL "arm64" )
+    set(ARCHNAME aarch64)
+    set(ARCH ARM)
+    set(WRDSZ 64)
+    set(TARGET_ARCHITECTURE aarch64)
+  endif()
 else()
   message("Unsupported OS: ${TARGET_OS}" )
   return()
diff --git a/runtime/CMakeLists.txt b/runtime/CMakeLists.txt
index d8285d1fc7a..098e56f5de0 100644
--- a/runtime/CMakeLists.txt
+++ b/runtime/CMakeLists.txt
@@ -29,6 +29,13 @@ add_definitions(
  -DPGI_LITTLE_ENDIAN
 )
 
+if( ${TARGET_OS} STREQUAL "OpenBSD" )
+  add_definitions(
+   -DTARGET_OPENBSD
+   -DOPENBSD
+  }
+endif()
+
 if( ${TARGET_ARCHITECTURE} STREQUAL "x86_64" )
   add_definitions(
    -DTARGET_X8664
diff --git a/runtime/flang/CMakeLists.txt b/runtime/flang/CMakeLists.txt
index c4300b9b2e7..0e928575e04 100644
--- a/runtime/flang/CMakeLists.txt
+++ b/runtime/flang/CMakeLists.txt
@@ -420,7 +420,7 @@ set(I8_FILES_DIR I8_sources)
 # Fortran files with macros as module names need to be preprocessed. 
 add_custom_command(
   OUTPUT "${I8_FILES_DIR}/ieee_arithmetic.F95"
-  COMMAND "${CMAKE_C_COMPILER}" -E 
+  COMMAND "${CMAKE_C_COMPILER}" -E -x c 
   "${CMAKE_CURRENT_SOURCE_DIR}/ieee_arithmetic.F95" -DDESC_I8 
   > "${I8_FILES_DIR}/ieee_arithmetic.F95"
   COMMENT "Preprocessing ieee_arithmetic.F95"
@@ -429,7 +429,7 @@ add_custom_command(
 
 add_custom_command(
   OUTPUT "${I8_FILES_DIR}/ieee_exceptions.F95"
-  COMMAND "${CMAKE_C_COMPILER}" -E 
+  COMMAND "${CMAKE_C_COMPILER}" -E -x c 
   "${CMAKE_CURRENT_SOURCE_DIR}/ieee_exceptions.F95" -DDESC_I8 
   > "${I8_FILES_DIR}/ieee_exceptions.F95"
   COMMENT "Preprocessing ieee_exceptions.F95"
diff --git a/runtime/flangrti/CMakeLists.txt b/runtime/flangrti/CMakeLists.txt
index 5f868afd3fe..2096e8d6531 100644
--- a/runtime/flangrti/CMakeLists.txt
+++ b/runtime/flangrti/CMakeLists.txt
@@ -113,6 +113,11 @@ find_library(
   HINTS ${CMAKE_BINARY_DIR}/lib)
 target_link_libraries(flangrti_shared ${LIBPGMATH})
 
+# BSDs need libexecinfo
+if( ${TARGET_OS} STREQUAL "OpenBSD" )
+  target_link_libraries(flangrti_shared ${FLANG_LIBEXECINFO})
+endif()
+
 if( ${TARGET_ARCHITECTURE} STREQUAL "aarch64" )
   target_compile_definitions(flangrti_static PRIVATE TARGET_LINUX_ARM)
   target_compile_definitions(flangrti_shared PRIVATE TARGET_LINUX_ARM)
diff --git a/runtime/flangrti/aarch64-Linux/dumpregs.c b/runtime/flangrti/aarch64-Linux/dumpregs.c
index 53eae37ceee..0e01806c908 100644
--- a/runtime/flangrti/aarch64-Linux/dumpregs.c
+++ b/runtime/flangrti/aarch64-Linux/dumpregs.c
@@ -15,6 +15,7 @@
  *
  */
 
+#ifndef TARGET_OPENBSD
 #include <sys/ucontext.h>
 
 void
@@ -29,3 +30,17 @@ getRegs(ucontext_t *u)
   return (gregset_t *)0;
 } 
 
+#else
+
+void
+dumpregs(void *regs)
+{
+}
+
+void *
+getRegs(void *u)
+{
+  return (void *)0;
+}
+
+#endif
diff --git a/runtime/flangrti/dumpregs.h b/runtime/flangrti/dumpregs.h
index ef84a58ed0e..fec640b0c26 100644
--- a/runtime/flangrti/dumpregs.h
+++ b/runtime/flangrti/dumpregs.h
@@ -21,6 +21,14 @@
  *  Declare routines that access the machine registers
  */
 
+#ifndef TARGET_OPENBSD
+
 void dumpregs(gregset_t *regs);
 gregset_t *getRegs(ucontext_t *u);
 
+#else
+
+void dumpregs(void *regs);
+void *getRegs(ucontext_t *u);
+
+#endif
diff --git a/runtime/flangrti/x86_64-Linux/dumpregs.c b/runtime/flangrti/x86_64-Linux/dumpregs.c
index 1b5e147b329..f66f82bc90a 100644
--- a/runtime/flangrti/x86_64-Linux/dumpregs.c
+++ b/runtime/flangrti/x86_64-Linux/dumpregs.c
@@ -15,7 +15,7 @@
  *
  */
 
-#if !defined(TARGET_WIN)
+#if !defined(TARGET_WIN) && !defined(TARGET_OPENBSD)
 #include <sys/ucontext.h>
 #endif
 #include "stdioInterf.h"
@@ -40,7 +40,7 @@
 #define RSP 15
 #define RIP 16
 
-#if defined(TARGET_OSX) || defined(TARGET_WIN)
+#if defined(TARGET_OSX) || defined(TARGET_WIN) || defined(TARGET_OPENBSD)
 /* no gregs and/or ucontext defined in for OSX or Windows */
 void * 
 getRegs(void *u)
diff --git a/tools/flang2/CMakeLists.txt b/tools/flang2/CMakeLists.txt
index ef8837c241d..a30aa299750 100644
--- a/tools/flang2/CMakeLists.txt
+++ b/tools/flang2/CMakeLists.txt
@@ -38,6 +38,11 @@ if( ${TARGET_OS} STREQUAL "Linux" )
     set(X86_64 ON)
     set(LINUX86 ON)
   endif()
+if( ${TARGET_OS} STREQUAL "OpenBSD" )
+  if( ${TARGET_ARCHITECTURE} STREQUAL "x86_64" )
+    set(X86_64 ON)
+    set(LINUX86 ON)
+  endif()
 endif()
 
 add_subdirectory(include)
diff --git a/tools/flang2/flang2exe/CMakeLists.txt b/tools/flang2/flang2exe/CMakeLists.txt
index 962a43e1428..2db7327c436 100644
--- a/tools/flang2/flang2exe/CMakeLists.txt
+++ b/tools/flang2/flang2exe/CMakeLists.txt
@@ -28,6 +28,12 @@ elseif( ${TARGET_ARCHITECTURE} STREQUAL "ppc64le" )
   )
 endif()
 
+if( ${TARGET_OS} STREQUAL "Linux" )
+  set(TARGET_CLASS "Linux")
+elseif( ${TARGET_OS} STREQUAL "OpenBSD" )
+  set(TARGET_CLASS "Linux")
+endif()
+
 
 set(SOURCES
   ${ARCH_DEP_FILES}
@@ -101,7 +107,7 @@ set(INCLUDE_DIRS
   ${FLANG_SOURCE_DIR}/lib/scutil
   ${CMAKE_CURRENT_SOURCE_DIR}
   ${CMAKE_CURRENT_BINARY_DIR}
-  ${CMAKE_CURRENT_SOURCE_DIR}/${TARGET_ARCHITECTURE}-${TARGET_OS}
+  ${CMAKE_CURRENT_SOURCE_DIR}/${TARGET_ARCHITECTURE}-${TARGET_CLASS}
   ${UTILS_SYMTAB_BIN_DIR}        # Symbol table headers
   ${UTILS_ILI_BIN_DIR}           # ILI IR headers
   ${UTILS_ILM_BIN_DIR}           # ILM IR headers