diff --git a/cmake/Modules/LAMMPSUtils.cmake b/cmake/Modules/LAMMPSUtils.cmake
index 2ec9d1b706..223577fe31 100644
--- a/cmake/Modules/LAMMPSUtils.cmake
+++ b/cmake/Modules/LAMMPSUtils.cmake
@@ -32,7 +32,13 @@ function(check_omp_h_include)
     set(CMAKE_REQUIRED_INCLUDES ${OpenMP_CXX_INCLUDE_DIRS})
     set(CMAKE_REQUIRED_LINK_OPTIONS ${OpenMP_CXX_FLAGS})
     set(CMAKE_REQUIRED_LIBRARIES ${OpenMP_CXX_LIBRARIES})
-    check_include_file_cxx(omp.h _have_omp_h)
+    # there are all kinds of problems with finding omp.h
+    # for Clang and derived compilers so we pretend it is there.
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+      set(_have_omp_h TRUE)
+    else()
+      check_include_file_cxx(omp.h _have_omp_h)
+    endif()
   else()
     set(_have_omp_h FALSE)
   endif()
diff --git a/tools/lammps-gui/CMakeLists.txt b/tools/lammps-gui/CMakeLists.txt
index 3609cf6297..940221886f 100644
--- a/tools/lammps-gui/CMakeLists.txt
+++ b/tools/lammps-gui/CMakeLists.txt
@@ -22,7 +22,13 @@ function(check_omp_h_include)
     set(CMAKE_REQUIRED_INCLUDES ${OpenMP_CXX_INCLUDE_DIRS})
     set(CMAKE_REQUIRED_LINK_OPTIONS ${OpenMP_CXX_FLAGS})
     set(CMAKE_REQUIRED_LIBRARIES ${OpenMP_CXX_LIBRARIES})
-    check_include_file_cxx(omp.h _have_omp_h)
+    # there are all kinds of problems with finding omp.h
+    # for Clang and derived compilers so we pretend it is there.
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+      set(_have_omp_h TRUE)
+    else()
+      check_include_file_cxx(omp.h _have_omp_h)
+    endif()
   else()
     set(_have_omp_h FALSE)
   endif()