diff --git a/indra/llcommon/CMakeLists.txt b/indra/llcommon/CMakeLists.txt
index 90a06561a8c1e7cd0e5bdbbd43d77b1ffd9f4d39..790adedfc686562c31f695c5df3f6c401175ab54 100644
--- a/indra/llcommon/CMakeLists.txt
+++ b/indra/llcommon/CMakeLists.txt
@@ -259,6 +259,9 @@ set(llcommon_HEADER_FILES
 if (DARWIN)
   list(APPEND llcommon_HEADER_FILES llsys_objc.h)
   list(APPEND llcommon_SOURCE_FILES llsys_objc.mm)
+
+  set_source_files_properties(llsys_objc.mm
+                              PROPERTIES SKIP_PRECOMPILE_HEADERS TRUE)
 endif (DARWIN)
 
 set_source_files_properties(${llcommon_HEADER_FILES}
diff --git a/indra/llfilesystem/CMakeLists.txt b/indra/llfilesystem/CMakeLists.txt
index e6fa0e313e7f236279e7a23a7e3a179a0ccd1858..18a3beb1278dc52b9d50240bd105551f4d50de51 100644
--- a/indra/llfilesystem/CMakeLists.txt
+++ b/indra/llfilesystem/CMakeLists.txt
@@ -34,6 +34,9 @@ if (DARWIN)
   LIST(APPEND llfilesystem_SOURCE_FILES lldir_utils_objc.h)
   LIST(APPEND llfilesystem_SOURCE_FILES lldir_mac.cpp)
   LIST(APPEND llfilesystem_HEADER_FILES lldir_mac.h)
+
+  set_source_files_properties(lldir_utils_objc.mm
+                            PROPERTIES SKIP_PRECOMPILE_HEADERS TRUE)
 endif (DARWIN)
 
 if (LINUX)
diff --git a/indra/llwindow/CMakeLists.txt b/indra/llwindow/CMakeLists.txt
index 95382d0e9fd76784d07e7d43fc25d2bf3b3d2010..b09dc0cc682bb1f01cd8f0e955587d8c8698eb3c 100644
--- a/indra/llwindow/CMakeLists.txt
+++ b/indra/llwindow/CMakeLists.txt
@@ -118,6 +118,11 @@ if (DARWIN)
     llopenglview-objc.h
     llappdelegate-objc.h
     )
+
+    set_source_files_properties(llwindowmacosx-objc.mm
+                                PROPERTIES SKIP_PRECOMPILE_HEADERS TRUE)
+    set_source_files_properties(llopenglview-objc.mm
+                                PROPERTIES SKIP_PRECOMPILE_HEADERS TRUE)
 endif (DARWIN)
 
 
diff --git a/indra/newview/CMakeLists.txt b/indra/newview/CMakeLists.txt
index 2bfcf7f920e48987bf9e590d453d90fbd04bf8bd..a9468f20892f1587195b23c4cf40425e57d25570 100644
--- a/indra/newview/CMakeLists.txt
+++ b/indra/newview/CMakeLists.txt
@@ -1466,6 +1466,7 @@ if (DARWIN)
   set_source_files_properties(
     llappdelegate-objc.mm
     PROPERTIES
+    SKIP_PRECOMPILE_HEADERS TRUE
     COMPILE_DEFINITIONS "${VIEWER_CHANNEL_VERSION_DEFINES}"
     # BugsplatMac is a module, imported with @import. That language feature
     # demands these -f switches.
@@ -1476,6 +1477,18 @@ if (DARWIN)
     COMPILE_FLAGS "-fmodules -fcxx-modules -Wno-nullability-completeness"
     )
 
+    set_source_files_properties(
+      llappviewermacosx-objc.mm
+      PROPERTIES 
+      SKIP_PRECOMPILE_HEADERS TRUE
+      )
+
+    set_source_files_properties(
+      llfilepicker_mac.mm
+      PROPERTIES 
+      SKIP_PRECOMPILE_HEADERS TRUE
+      )
+
   find_library(APPKIT_LIBRARY AppKit)
   find_library(COCOA_LIBRARY Cocoa)
   find_library(IOKIT_LIBRARY IOKit)