--- a/config/config.mk
+++ b/config/config.mk
@@ -307,18 +307,18 @@ endif # CLANG_CL
 
 # Use warnings-as-errors if ALLOW_COMPILER_WARNINGS is not set to 1 (which
 # includes the case where it's undefined).
 ifneq (1,$(ALLOW_COMPILER_WARNINGS))
 CXXFLAGS += $(WARNINGS_AS_ERRORS)
 CFLAGS   += $(WARNINGS_AS_ERRORS)
 endif # ALLOW_COMPILER_WARNINGS
 
-COMPILE_CFLAGS	= $(COMPUTED_CFLAGS) $(DSO_CFLAGS) $(DSO_PIC_CFLAGS) $(RTL_FLAGS) $(OS_COMPILE_CFLAGS) $(_DEPEND_CFLAGS) $(CFLAGS) $(MOZBUILD_CFLAGS) $(MK_COMPILE_DEFINES)
-COMPILE_CXXFLAGS = $(COMPUTED_CXXFLAGS) $(DSO_CFLAGS) $(DSO_PIC_CFLAGS) $(RTL_FLAGS) $(OS_COMPILE_CXXFLAGS) $(_DEPEND_CFLAGS) $(CXXFLAGS) $(MOZBUILD_CXXFLAGS) $(MK_COMPILE_DEFINES)
+COMPILE_CFLAGS	= $(COMPUTED_CFLAGS) $(RTL_FLAGS) $(OS_COMPILE_CFLAGS) $(_DEPEND_CFLAGS) $(CFLAGS) $(MOZBUILD_CFLAGS) $(MK_COMPILE_DEFINES)
+COMPILE_CXXFLAGS = $(COMPUTED_CXXFLAGS) $(RTL_FLAGS) $(OS_COMPILE_CXXFLAGS) $(_DEPEND_CFLAGS) $(CXXFLAGS) $(MOZBUILD_CXXFLAGS) $(MK_COMPILE_DEFINES)
 COMPILE_CMFLAGS = $(OS_COMPILE_CMFLAGS) $(MOZBUILD_CMFLAGS)
 COMPILE_CMMFLAGS = $(OS_COMPILE_CMMFLAGS) $(MOZBUILD_CMMFLAGS)
 ASFLAGS += $(MOZBUILD_ASFLAGS)
 
 ifndef CROSS_COMPILE
 HOST_CFLAGS += $(RTL_FLAGS)
 endif
 

--- a/python/mozbuild/mozbuild/compilation/database.py
+++ b/python/mozbuild/mozbuild/compilation/database.py
@@ -191,18 +191,16 @@ class CompileDBBackend(CommonBackend):
             if not value:
                 return
             if isinstance(value, types.StringTypes):
                 value = value.split()
             db.extend(value)
 
         db.append('$(COMPUTED_%s)' % self.CFLAGS[canonical_suffix])
 
-        append_var('DSO_CFLAGS')
-        append_var('DSO_PIC_CFLAGS')
         if canonical_suffix in ('.c', '.cpp'):
             db.append('$(RTL_FLAGS)')
         append_var('OS_COMPILE_%s' % self.CFLAGS[canonical_suffix])
         append_var('OS_CPPFLAGS')
         append_var('OS_%s' % self.CFLAGS[canonical_suffix])
         append_var('MOZ_DEBUG_FLAGS')
         append_var('MOZ_OPTIMIZE_FLAGS')
         append_var('MOZ_FRAMEPTR_FLAGS')

--- a/python/mozbuild/mozbuild/frontend/context.py
+++ b/python/mozbuild/mozbuild/frontend/context.py
@@ -314,16 +314,20 @@ class CompileFlags(ContextDerivedValue, 
              ('CXXFLAGS', 'CFLAGS')),
             ('LOCAL_INCLUDES', None, ('CXXFLAGS', 'CFLAGS')),
             ('EXTRA_INCLUDES', ['-I%s/dist/include' % context.config.topobjdir],
              ('CXXFLAGS', 'CFLAGS')),
             ('OS_INCLUDES', list(itertools.chain(*(context.config.substs.get(v, []) for v in (
                 'NSPR_CFLAGS', 'NSS_CFLAGS', 'MOZ_JPEG_CFLAGS', 'MOZ_PNG_CFLAGS',
                 'MOZ_ZLIB_CFLAGS', 'MOZ_PIXMAN_CFLAGS')))),
              ('CXXFLAGS', 'CFLAGS')),
+            ('DSO', context.config.substs.get('DSO_CFLAGS'),
+             ('CXXFLAGS', 'CFLAGS')),
+            ('DSO_PIC', context.config.substs.get('DSO_PIC_CFLAGS'),
+             ('CXXFLAGS', 'CFLAGS')),
         )
         self._known_keys = set(k for k, v, _ in self.flag_variables)
 
         # Providing defaults here doesn't play well with multiple templates
         # modifying COMPILE_FLAGS from the same moz.build, because the merge
         # done after the template runs can't tell which values coming from
         # a template were set and which were provided as defaults.
         template_name = getattr(context, 'template', None)