diff --git a/libcxx/test/std/depr/depr.c.headers/uchar_h.compile.pass.cpp b/libcxx/test/std/depr/depr.c.headers/uchar_h.compile.pass.cpp
index a1560c8ee5853..2b64554666817 100644
--- a/libcxx/test/std/depr/depr.c.headers/uchar_h.compile.pass.cpp
+++ b/libcxx/test/std/depr/depr.c.headers/uchar_h.compile.pass.cpp
@@ -11,9 +11,6 @@
 // Apple platforms don't provide <uchar.h> yet, so these tests fail.
 // XFAIL: target={{.+}}-apple-{{.+}}
 
-// mbrtoc16 not defined.
-// XFAIL: LIBCXX-PICOLIBC-FIXME
-
 // <uchar.h>
 
 #include <uchar.h>
diff --git a/libcxx/test/std/strings/c.strings/cuchar.compile.pass.cpp b/libcxx/test/std/strings/c.strings/cuchar.compile.pass.cpp
index 2076384deb2b2..db00cbde33365 100644
--- a/libcxx/test/std/strings/c.strings/cuchar.compile.pass.cpp
+++ b/libcxx/test/std/strings/c.strings/cuchar.compile.pass.cpp
@@ -11,9 +11,6 @@
 // Apple platforms don't provide <uchar.h> yet, so these tests fail.
 // XFAIL: target={{.+}}-apple-{{.+}}
 
-// mbrtoc16 not defined.
-// XFAIL: LIBCXX-PICOLIBC-FIXME
-
 // <cuchar>
 
 #include <cuchar>
diff --git a/libcxx/utils/ci/build-picolibc.sh b/libcxx/utils/ci/build-picolibc.sh
index 521c1bef9fc7e..6743bf2e20396 100755
--- a/libcxx/utils/ci/build-picolibc.sh
+++ b/libcxx/utils/ci/build-picolibc.sh
@@ -70,7 +70,7 @@ picolibc_build_dir="${build_dir}/picolibc-build"
 mkdir -p "${picolibc_source_dir}"
 mkdir -p "${picolibc_build_dir}"
 # Download a known good version of picolibc.
-picolibc_commit="48fbc2009c6473293d03d5ec6f190565c6223a5c"
+picolibc_commit="db4d0fe5952d5ecd714781e3212d4086d970735a"
 curl -L "https://github.com/picolibc/picolibc/archive/${picolibc_commit}.zip" --output "${picolibc_source_dir}/picolibc.zip"
 unzip -q "${picolibc_source_dir}/picolibc.zip" -d "${picolibc_source_dir}"
 mv "${picolibc_source_dir}/picolibc-${picolibc_commit}"/* "${picolibc_source_dir}"