diff --git a/.github/workflows/root-ci-config/build_root.py b/.github/workflows/root-ci-config/build_root.py
index 9462d0f2ab36a..14390ba90ea1d 100755
--- a/.github/workflows/root-ci-config/build_root.py
+++ b/.github/workflows/root-ci-config/build_root.py
@@ -59,7 +59,7 @@ def main():
         # the target branch in the ROOT repository using base_ref and head_ref:
         # - The base_ref is e.g. "master" or "v6-38-00-patches" 
         # - The head_ref for PRs is formatted as <PR branch>:<Fork branch> e.g. "refs/pull/20742/head:cppyy_fixup"
-        if not ":" in args.head_ref:
+        if ":" not in args.head_ref:
             build_utils.print_error(f"This has been identified as a PR build. However, the head-ref is {args.head_ref}.")
         branch_in_fork = args.head_ref.split(":")[-1]
         if branch_in_fork == args.base_ref:
@@ -85,7 +85,7 @@ def main():
 
     if "minimal" in platform_options and platform_options["minimal"] == "ON":
         options_dict = platform_options
-        print(f"Minimal build detected in the platform options. Ignoring global configuration.")
+        print("Minimal build detected in the platform options. Ignoring global configuration.")
     else:
         options_dict.update(platform_options)
         print(f"Build option overrides for {args.platform_config}:")
@@ -413,26 +413,13 @@ 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}")
@@ -460,10 +447,7 @@ 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 7945ee63a3078..68354572d3301 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -469,6 +469,15 @@ 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.