diff --git a/LLVM.makefile b/LLVM.makefile
index cef5095a..d002a44a 100644
--- a/LLVM.makefile
+++ b/LLVM.makefile
@@ -74,6 +74,7 @@ $(BUILD_DIR)/llvm.BUILT:
 		install-llvm-ranlib \
 		install-llvm-strip \
 		install-llvm-dwarfdump \
+		install-llvm-symbolizer \
 		install-clang-resource-headers \
 		install-ar \
 		install-ranlib \
diff --git a/faasmtools/build.py b/faasmtools/build.py
index ffa45d39..e3d7a931 100644
--- a/faasmtools/build.py
+++ b/faasmtools/build.py
@@ -73,6 +73,7 @@
 WASM_CFLAGS = [
     "-O3",
     # "-mno-atomics",
+    # TODO: may want to use -mrelaxed-simd instead
     "-msimd128",
     "--sysroot={}".format(WASM_SYSROOT),
     "-m32",
diff --git a/sysroot_extras/libc.imports b/sysroot_extras/libc.imports
index 581cc36b..d0ef7134 100644
--- a/sysroot_extras/libc.imports
+++ b/sysroot_extras/libc.imports
@@ -99,11 +99,16 @@ pthread_cond_destroy
 pthread_cond_signal
 pthread_cond_timedwait
 pthread_cond_init
+pthread_condattr_init
+pthread_condattr_setclock
 pthread_equal
 pthread_mutexattr_init
 pthread_mutexattr_settype
 pthread_mutexattr_destroy
+__tls_align
 __tls_base
+__tls_size
+__wasm_init_tls
 
 # Signals
 signal
diff --git a/third-party/wasi-libc b/third-party/wasi-libc
index b37edadc..dceadb68 160000
--- a/third-party/wasi-libc
+++ b/third-party/wasi-libc
@@ -1 +1 @@
-Subproject commit b37edadc81a9c24b3c4c93f1ba8e14210144832f
+Subproject commit dceadb68111821fc2ba9ba3a64b95463b21cd9db