diff --git a/submodules/externals/build/webrtc/modules/audio_coding/codecs/isac/fix/source/Android.mk b/submodules/externals/build/webrtc/modules/audio_coding/codecs/isac/fix/source/Android.mk
index 6fad2d78e..e4d20f758 100644
--- a/submodules/externals/build/webrtc/modules/audio_coding/codecs/isac/fix/source/Android.mk
+++ b/submodules/externals/build/webrtc/modules/audio_coding/codecs/isac/fix/source/Android.mk
@@ -53,7 +53,8 @@ LOCAL_SRC_FILES += \
     pitch_filter_armv6.S
 else
 LOCAL_SRC_FILES += \
-    lattice_c.c
+    lattice_c.c \
+    pitch_filter_c.c
 endif
 
 # Flags passed to both C and C++ files.