diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index a778c89d42..06297ca919 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -769,6 +769,13 @@ endif()
 include(Testing)
 include(CodeCoverage)
 include(CodingStandard)
+find_package(ClangFormat 8.0)
+
+if(ClangFormat_FOUND)
+  add_custom_target(format-src
+    COMMAND ${ClangFormat_EXECUTABLE} --verbose -i -style=file *.cpp *.h */*.cpp */*.h
+    WORKING_DIRECTORY ${LAMMPS_SOURCE_DIR})
+endif()
 
 get_target_property(DEFINES lammps COMPILE_DEFINITIONS)
 include(FeatureSummary)
diff --git a/unittest/CMakeLists.txt b/unittest/CMakeLists.txt
index 2d86fa2663..bb746c13ec 100644
--- a/unittest/CMakeLists.txt
+++ b/unittest/CMakeLists.txt
@@ -55,9 +55,7 @@ add_subdirectory(force-styles)
 find_package(ClangFormat 8.0)
 
 if(ClangFormat_FOUND)
-  set(UNITTEST_SOURCES)
-  file(GLOB_RECURSE UNITTEST_SOURCES *.cpp *.h)
   add_custom_target(format-tests
-    COMMAND ${ClangFormat_EXECUTABLE} --verbose -i -style=file ${UNITTEST_SOURCES}
-    DEPENDS ${UNITTEST_SOURCES})
+    COMMAND ${ClangFormat_EXECUTABLE} --verbose -i -style=file */*.cpp */*.h
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 endif()