diff --git a/Makefile b/Makefile
index 89f77d3d..42eacb22 100644
--- a/Makefile
+++ b/Makefile
@@ -370,6 +370,7 @@ ifeq ($(THREAD_MODEL), single)
 LIBC_TOP_HALF_MUSL_SOURCES += \
     $(addprefix $(LIBC_TOP_HALF_MUSL_SRC_DIR)/, \
         thread/default_attr.c \
+        thread/pthread_atfork.c \
         thread/pthread_attr_destroy.c \
         thread/pthread_attr_get.c \
         thread/pthread_attr_init.c \
diff --git a/expected/wasm32-wasip1/defined-symbols.txt b/expected/wasm32-wasip1/defined-symbols.txt
index 99bbd244..a8ffc8e6 100644
--- a/expected/wasm32-wasip1/defined-symbols.txt
+++ b/expected/wasm32-wasip1/defined-symbols.txt
@@ -951,6 +951,7 @@ program_invocation_name
 program_invocation_short_name
 pselect
 psignal
+pthread_atfork
 pthread_attr_destroy
 pthread_attr_getdetachstate
 pthread_attr_getguardsize