diff --git a/coreconf/config.gypi b/coreconf/config.gypi
index da5a483050..0fd31ec678 100644
--- a/coreconf/config.gypi
+++ b/coreconf/config.gypi
@@ -218,7 +218,7 @@
               '-Wl,--version-script,<(INTERMEDIATE_DIR)/out.>(mapfile)',
             ],
           }],
-          [ 'OS=="win"', {
+          [ 'cc_use_gnu_ld!=1 and OS=="win"', {
             # On Windows, .def files are used directly as sources.
             'sources': [
               '>(mapfile)',
diff --git a/lib/freebl/freebl.gyp b/lib/freebl/freebl.gyp
index e83d6ec837..f75474252b 100644
--- a/lib/freebl/freebl.gyp
+++ b/lib/freebl/freebl.gyp
@@ -174,6 +174,7 @@
           'VCCLCompilerTool': {
             #TODO: -Ox optimize flags
             'PreprocessorDefinitions': [
+              # Should be copied to mingw defines below
               'MP_IS_LITTLE_ENDIAN',
               'NSS_BEVAND_ARCFOUR',
               'MPI_AMD64',
@@ -185,6 +186,17 @@
           },
         },
       }],
+      [ 'cc_use_gnu_ld==1 and OS=="win" and target_arch=="x64"', {
+        'defines': [
+          'MP_IS_LITTLE_ENDIAN',
+          'NSS_BEVAND_ARCFOUR',
+          'MPI_AMD64',
+          'MP_ASSEMBLY_MULTIPLY',
+          'NSS_USE_COMBA',
+          'USE_HW_AES',
+          'INTEL_GCM',
+         ],
+      }],
       [ 'OS!="win"', {
         'conditions': [
           [ 'target_arch=="x64" or target_arch=="arm64" or target_arch=="aarch64"', {
diff --git a/lib/freebl/freebl_base.gypi b/lib/freebl/freebl_base.gypi
index bf7dd56ac0..027aa2702c 100644
--- a/lib/freebl/freebl_base.gypi
+++ b/lib/freebl/freebl_base.gypi
@@ -106,7 +106,7 @@
         'advapi32.lib',
       ],
       'conditions': [
-        [ 'target_arch=="x64"', {
+        [ 'cc_use_gnu_ld!=1 and target_arch=="x64"', {
           'sources': [
             'arcfour-amd64-masm.asm',
             'mpi/mpi_amd64.c',
@@ -115,7 +115,8 @@
             'intel-aes-x64-masm.asm',
             'intel-gcm-x64-masm.asm',
           ],
-        }, {
+        }],
+	      [ 'cc_use_gnu_ld!=1 and target_arch!="x64"', {
           # not x64
           'sources': [
             'mpi/mpi_x86_asm.c',