diff --git a/app/src/main/assets/config b/app/src/main/assets/config
index cf9e11d9..f99ef8af 100644
--- a/app/src/main/assets/config
+++ b/app/src/main/assets/config
@@ -27,6 +27,7 @@ module g722.so
 module g7221.so
 module g726.so
 module g729.so
+module gsm.so
 module g711.so
 module webrtc_aecm.so
 module opensles.so
diff --git a/app/src/main/cpp/CMakeLists.txt b/app/src/main/cpp/CMakeLists.txt
index 70ebf7e6..f390f3fc 100644
--- a/app/src/main/cpp/CMakeLists.txt
+++ b/app/src/main/cpp/CMakeLists.txt
@@ -36,6 +36,10 @@ add_library(lib_g729 STATIC IMPORTED)
 set_target_properties(lib_g729 PROPERTIES IMPORTED_LOCATION
         ${distribution_DIR}/g729/lib/${ANDROID_ABI}/libbcg729.a)
 
+add_library(lib_gsm STATIC IMPORTED)
+set_target_properties(lib_gsm PROPERTIES IMPORTED_LOCATION
+        ${distribution_DIR}/gsm/lib/${ANDROID_ABI}/libgsm.a)
+
 add_library(lib_amrnb STATIC IMPORTED)
 set_target_properties(lib_amrnb PROPERTIES IMPORTED_LOCATION
         ${distribution_DIR}/amr/lib/${ANDROID_ABI}/libamrnb.a)
@@ -82,6 +86,7 @@ target_link_libraries(baresip
         lib_spandsp
         lib_g722_1
         lib_g729
+        lib_gsm
         lib_amrnb
         lib_amrwb
         lib_amrwbenc
diff --git a/app/src/main/kotlin/com/tutpro/baresip/Config.kt b/app/src/main/kotlin/com/tutpro/baresip/Config.kt
index 6dd1dc78..8e73a2cc 100644
--- a/app/src/main/kotlin/com/tutpro/baresip/Config.kt
+++ b/app/src/main/kotlin/com/tutpro/baresip/Config.kt
@@ -20,6 +20,10 @@ object Config {
 
         config = config.replace("module zrtp.so", "module gzrtp.so")
 
+        if (!config.contains("module gsm.so")) {
+            config = "${config}module gsm.so\n"
+        }
+
         if (config.contains("rtp_stats no"))
             replaceVariable("rtp_stats", "yes")