diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index 1f29689f46..bdd1d45187 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -248,11 +248,15 @@ if(BUILD_OMP)
     message(FATAL_ERROR "Cannot find the 'omp.h' header file required for full OpenMP support")
   endif()
 
-  if ((CMAKE_CXX_COMPILER_ID STREQUAL "GNU") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 8.99.9))
-    # GCC 9.x strictly implements OpenMP 4.0 semantics for consts.
-    add_definitions(-DLAMMPS_OMP_COMPAT=4)
+  if (((CMAKE_CXX_COMPILER_ID STREQUAL "GNU") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 8.99.9)) OR
+      ((CMAKE_CXX_COMPILER_ID STREQUAL "Clang") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 9.99.9)) OR
+      ((CMAKE_CXX_COMPILER_ID STREQUAL "Intel") AND (CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 18.99.9))
+      )
+    # GCC 9.x and later plus Clang 10.x and later implement strict OpenMP 4.0 semantics for consts.
+    # Intel 18.0 was tested to support both, so we switch to OpenMP 4+ from 19.x onward to be safe.
+    target_compile_definitions(lammps PRIVATE -DLAMMPS_OMP_COMPAT=4)
   else()
-    add_definitions(-DLAMMPS_OMP_COMPAT=3)
+    target_compile_definitions(lammps PRIVATE -DLAMMPS_OMP_COMPAT=3)
   endif()
   target_link_libraries(lammps PRIVATE OpenMP::OpenMP_CXX)
 endif()
diff --git a/src/omp_compat.h b/src/omp_compat.h
index add429eea8..d80d6f6f7f 100644
--- a/src/omp_compat.h
+++ b/src/omp_compat.h
@@ -23,8 +23,8 @@
 //
 // To date, most compilers still accept the OpenMP 3.0 form,
 // so this is what LAMMPS primarily uses.  For those compilers
-// that strictly implement OpenMP 4.0 (such as GCC 9.0), we
-// give up default(none).
+// that strictly implement OpenMP 4.0 (such as GCC 9.0 and later
+// or Clang 10.0 and later), we give up default(none).
 #if LAMMPS_OMP_COMPAT == 4
 #    define LMP_SHARED(...)
 #    define LMP_DEFAULT_NONE default(shared)