diff --git a/.github/workflows/root-ci-config/build_root.py b/.github/workflows/root-ci-config/build_root.py
index 91e50979b86be..8497261d3d443 100755
--- a/.github/workflows/root-ci-config/build_root.py
+++ b/.github/workflows/root-ci-config/build_root.py
@@ -419,26 +419,13 @@ def cmake_configure(options, buildtype):
     options = f"{options} -DROOT_COMPILEDATA_IGNORE_BUILD_NODE_CHANGES=ON"
 
     result = subprocess_with_log(f"""
-        cmake -S '{srcdir}' -B '{builddir}' -DCMAKE_BUILD_TYPE={buildtype} {options}
+        cmake --fresh -S '{srcdir}' -B '{builddir}' -DCMAKE_BUILD_TYPE={buildtype} {options}
     """)
 
     if result != 0:
         die(result, "Failed cmake generation step")
 
 
-@github_log_group("Dump existing configuration")
-def cmake_dump_config():
-    # Print CMake cached config
-    srcdir = os.path.join(WORKDIR, "src")
-    builddir = os.path.join(WORKDIR, "build")
-    result = subprocess_with_log(f"""
-        cmake -S '{srcdir}' -B '{builddir}' -N -L
-    """)
-
-    if result != 0:
-        die(result, "Failed cmake cache print step")
-
-
 @github_log_group("Dump requested build configuration")
 def dump_requested_config(options):
     print(f"\nBUILD OPTIONS: {options}")
@@ -466,10 +453,7 @@ def build(options, buildtype):
         if result != 0:
             die(result, "Failed to create build directory")
 
-    if not os.path.exists(os.path.join(WORKDIR, "build", "CMakeCache.txt")):
-        cmake_configure(options, buildtype)
-    else:
-        cmake_dump_config()
+    cmake_configure(options, buildtype)
 
     dump_requested_config(options)
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index feb1dcaad6d3b..2ab3fdce03664 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -467,6 +467,15 @@ if(MSVC)
 endif()
 
 if(runtime_cxxmodules)
+  if(NOT ROOT_CONFIGURED_FROM_CACHE)
+    # When using cmake --fresh (or changing the toolchain), remove possibly stale pcms that are not tracked by CMake
+    set(ROOT_CONFIGURED_FROM_CACHE True CACHE BOOL "Shows if ROOT is configured from an existing CMake cache")
+    mark_as_advanced(ROOT_CONFIGURED_FROM_CACHE)
+    file(GLOB_RECURSE left_over_pcms ${CMAKE_BINARY_DIR}/*.pcm)
+    if(left_over_pcms)
+      file(REMOVE ${left_over_pcms})
+    endif()
+  endif()
   # Dummy target that does nothing, we don't need a PCH for modules.
   # Onepcm target has all dependencies needed for allDict.cxx.pch, which allow
   # to test hsimple.C after all C++ modules are updated.