diff --git a/Makefile b/Makefile
index 7e43524..55f8023 100644
--- a/Makefile
+++ b/Makefile
@@ -520,86 +520,6 @@ endif
 SYSROOT_INC = $(SYSROOT)/include/$(TARGET_TRIPLE)
 SYSROOT_SHARE = $(SYSROOT)/share/$(TARGET_TRIPLE)
 
-# Files from musl's include directory that we don't want to install in the
-# sysroot's include directory.
-MUSL_OMIT_HEADERS :=
-
-# Remove files which aren't headers (we generate alltypes.h below).
-MUSL_OMIT_HEADERS += \
-    "bits/syscall.h.in" \
-    "bits/alltypes.h.in" \
-    "alltypes.h.in"
-
-# Use the compiler's version of these headers.
-MUSL_OMIT_HEADERS += \
-    "stdarg.h" \
-    "stddef.h"
-
-# Use the WASI errno definitions.
-MUSL_OMIT_HEADERS += \
-    "bits/errno.h"
-
-# Remove headers that aren't supported yet or that aren't relevant for WASI.
-MUSL_OMIT_HEADERS += \
-    "sys/procfs.h" \
-    "sys/user.h" \
-    "sys/kd.h" "sys/vt.h" "sys/soundcard.h" "sys/sem.h" \
-    "sys/shm.h" "sys/msg.h" "sys/ipc.h" "sys/ptrace.h" \
-    "sys/statfs.h" \
-    "bits/kd.h" "bits/vt.h" "bits/soundcard.h" "bits/sem.h" \
-    "bits/shm.h" "bits/msg.h" "bits/ipc.h" "bits/ptrace.h" \
-    "bits/statfs.h" \
-    "sys/vfs.h" \
-    "syslog.h" "sys/syslog.h" \
-    "wait.h" "sys/wait.h" \
-    "ucontext.h" "sys/ucontext.h" \
-    "paths.h" \
-    "utmp.h" "utmpx.h" \
-    "lastlog.h" \
-    "sys/acct.h" \
-    "sys/cachectl.h" \
-    "sys/epoll.h" "sys/reboot.h" "sys/swap.h" \
-    "sys/sendfile.h" "sys/inotify.h" \
-    "sys/quota.h" \
-    "sys/klog.h" \
-    "sys/fsuid.h" \
-    "sys/io.h" \
-    "sys/prctl.h" \
-    "sys/mtio.h" \
-    "sys/mount.h" \
-    "sys/fanotify.h" \
-    "sys/personality.h" \
-    "elf.h" "link.h" "bits/link.h" \
-    "scsi/scsi.h" "scsi/scsi_ioctl.h" "scsi/sg.h" \
-    "sys/auxv.h" \
-    "pwd.h" "shadow.h" "grp.h" \
-    "mntent.h" \
-    "resolv.h" \
-    "pty.h" \
-    "ulimit.h" \
-    "sys/xattr.h" \
-    "wordexp.h" \
-    "spawn.h" \
-    "sys/membarrier.h" \
-    "sys/signalfd.h" \
-    "termios.h" \
-    "sys/termios.h" \
-    "bits/termios.h" \
-    "net/if.h" \
-    "net/if_arp.h" \
-    "net/ethernet.h" \
-    "net/route.h" \
-    "netinet/if_ether.h" \
-    "netinet/ether.h" \
-    "sys/timerfd.h" \
-    "libintl.h" \
-    "sys/sysmacros.h" \
-    "aio.h"
-
-ifeq ($(WASI_SNAPSHOT), p1)
-MUSL_OMIT_HEADERS += "netdb.h"
-endif
-
 default: finish
 
 LIBC_SO_OBJS = $(patsubst %.o,%.pic.o,$(filter-out $(MUSL_PRINTSCAN_OBJS),$(LIBC_OBJS)))
@@ -811,33 +731,8 @@ $(INCLUDE_DIRS): $(ALL_POSSIBLE_HEADERS)
 	#
 	# Install the include files.
 	#
-	mkdir -p "$(SYSROOT_INC)"
-	cp -r "$(LIBC_BOTTOM_HALF_HEADERS_PUBLIC)"/* "$(SYSROOT_INC)"
-
-	# Generate musl's bits/alltypes.h header.
-	mkdir -p "$(SYSROOT_INC)/bits"
-	sed -f $(LIBC_TOP_HALF_MUSL_DIR)/tools/mkalltypes.sed \
-	    $(LIBC_TOP_HALF_MUSL_DIR)/arch/wasm32/bits/alltypes.h.in \
-	    $(LIBC_TOP_HALF_MUSL_DIR)/include/alltypes.h.in \
-	    > "$(SYSROOT_INC)/bits/alltypes.h"
-
-	# Copy in the bulk of musl's public header files.
-	cp -r "$(LIBC_TOP_HALF_MUSL_INC)"/* "$(SYSROOT_INC)"
-
-	# Copy in the musl's "bits" header files.
-	cp -r "$(LIBC_TOP_HALF_MUSL_DIR)"/arch/generic/bits/* "$(SYSROOT_INC)/bits"
-	cp -r "$(LIBC_TOP_HALF_MUSL_DIR)"/arch/wasm32/bits/* "$(SYSROOT_INC)/bits"
-
-	# Copy in the fts header files.
-	cp "$(MUSL_FTS_SRC_DIR)/fts.h" "$(SYSROOT_INC)/fts.h"
-
-	# Remove selected header files.
-	$(RM) $(patsubst %,$(SYSROOT_INC)/%,$(MUSL_OMIT_HEADERS))
-ifeq ($(WASI_SNAPSHOT), p2)
-	printf '#ifndef __wasilibc_use_wasip2\n#define __wasilibc_use_wasip2\n#endif\n' \
-		> "$(SYSROOT_INC)/__wasi_snapshot.h"
-endif
-
+	SYSROOT_INC=$(SYSROOT_INC) TARGET_TRIPLE=$(TARGET_TRIPLE) \
+	    $(CURDIR)/scripts/install-include-headers.sh
 	# Stamp the include installation.
 	@mkdir -p $(@D)
 	touch $@
diff --git a/scripts/install-include-headers.sh b/scripts/install-include-headers.sh
new file mode 100755
index 0000000..efa48aa
--- /dev/null
+++ b/scripts/install-include-headers.sh
@@ -0,0 +1,86 @@
+#!/usr/bin/env bash
+#
+# Install all the necessary necessary include files from wasi-libc
+# (`$WASI_LIBC`) into the sysroot include directory (`$SYSROOT_INC`). It uses a
+# passed target triple (`$TARGET_TRIPLE`) to condition some of the
+# copied/generated files.
+#
+# Usage: SYSROOT_INC=... TARGET_TRIPLE=... ./install-include-headers.sh
+
+set -euo pipefail
+
+PARENT_DIR=$(dirname $(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &> /dev/null && pwd))
+WASI_LIBC="${WASI_LIBC:-$PARENT_DIR}"
+if [[ -z "${SYSROOT_INC}" || -z "${TARGET_TRIPLE}" ]]; then
+    echo "usage: SYSROOT_INC=... TARGET_TRIPLE=... ./install-include-headers.sh"
+    exit 1
+fi
+# The commands are available for override to allow dry runs.
+CP="${CP:-cp -v}"
+RM="${RM:-rm -v}"
+MKDIR="${MKDIR:-mkdir}"
+SED="${SED:-sed}"
+
+# Copy in the bottom half's public headers.
+$MKDIR -p $SYSROOT_INC
+$CP -r $WASI_LIBC/libc-bottom-half/headers/public/* $SYSROOT_INC
+
+# Copy in the bulk of musl's public header files.
+$CP -r $WASI_LIBC/libc-top-half/musl/include/* $SYSROOT_INC
+
+# Copy in the musl's "bits" header files.
+$MKDIR -p $SYSROOT_INC/bits
+$CP -r $WASI_LIBC/libc-top-half/musl/arch/generic/bits/* $SYSROOT_INC/bits
+$CP -r $WASI_LIBC/libc-top-half/musl/arch/wasm32/bits/* $SYSROOT_INC/bits
+
+# Generate musl's bits/alltypes.h header.
+(set -x; $SED -f $WASI_LIBC/libc-top-half/musl/tools/mkalltypes.sed \
+    $WASI_LIBC/libc-top-half/musl/arch/wasm32/bits/alltypes.h.in \
+    $WASI_LIBC/libc-top-half/musl/include/alltypes.h.in \
+    > $SYSROOT_INC/bits/alltypes.h)
+
+# Copy in the fts header files.
+$CP $WASI_LIBC/fts/musl-fts/fts.h $SYSROOT_INC/fts.h
+
+# Remove selected header files. These are files from musl's include directory
+# that we don't want to install in the sysroot's include directory.
+MUSL_OMIT_HEADERS=()
+# Remove files which aren't headers (we generate `alltypes.h` above).
+MUSL_OMIT_HEADERS+=("bits/syscall.h.in" "bits/alltypes.h.in" "alltypes.h.in")
+# Use the compiler's version of these headers.
+MUSL_OMIT_HEADERS+=("stdarg.h" "stddef.h")
+# Use the WASI errno definitions.
+MUSL_OMIT_HEADERS+=("bits/errno.h")
+# Remove headers that aren't supported yet or that aren't relevant for WASI.
+MUSL_OMIT_HEADERS+=("sys/procfs.h" "sys/user.h" "sys/kd.h" "sys/vt.h" \
+    "sys/soundcard.h" "sys/sem.h" "sys/shm.h" "sys/msg.h" "sys/ipc.h" \
+    "sys/ptrace.h" "sys/statfs.h" "bits/kd.h" "bits/vt.h" "bits/soundcard.h" \
+    "bits/sem.h" "bits/shm.h" "bits/msg.h" "bits/ipc.h" "bits/ptrace.h" \
+    "bits/statfs.h" "sys/vfs.h" "syslog.h" "sys/syslog.h" "wait.h" \
+    "sys/wait.h" "ucontext.h" "sys/ucontext.h" "paths.h" "utmp.h" "utmpx.h" \
+    "lastlog.h" "sys/acct.h" "sys/cachectl.h" "sys/epoll.h" "sys/reboot.h" \
+    "sys/swap.h" "sys/sendfile.h" "sys/inotify.h" "sys/quota.h" "sys/klog.h" \
+    "sys/fsuid.h" "sys/io.h" "sys/prctl.h" "sys/mtio.h" "sys/mount.h" \
+    "sys/fanotify.h" "sys/personality.h" "elf.h" "link.h" "bits/link.h" \
+    "scsi/scsi.h" "scsi/scsi_ioctl.h" "scsi/sg.h" "sys/auxv.h" "pwd.h" \
+    "shadow.h" "grp.h" "mntent.h" "resolv.h" "pty.h" "ulimit.h" "sys/xattr.h" \
+    "wordexp.h" "spawn.h" "sys/membarrier.h" "sys/signalfd.h" "termios.h" \
+    "sys/termios.h" "bits/termios.h" "net/if.h" "net/if_arp.h" \
+    "net/ethernet.h" "net/route.h" "netinet/if_ether.h" "netinet/ether.h" \
+    "sys/timerfd.h" "libintl.h" "sys/sysmacros.h" "aio.h")
+# Exclude `netdb.h` from all of the p1 targets.
+if [[ $TARGET_TRIPLE == *"wasi" || $TARGET_TRIPLE == *"wasi-threads" || \
+      $TARGET_TRIPLE == *"wasip1" || $TARGET_TRIPLE == *"wasip1-threads" ]]; then
+    MUSL_OMIT_HEADERS+=("netdb.h")
+fi
+
+# Remove all the `MUSL_OMIT_HEADERS` previously copied over.
+for OMIT_HEADER in "${MUSL_OMIT_HEADERS[@]}"; do
+    $RM -f $SYSROOT_INC/$OMIT_HEADER
+done
+
+# Update the `__wasi_snapshot.h` with some additional p2 definitions.
+if [[ $TARGET_TRIPLE == *"p2" ]]; then
+    printf '#ifndef __wasilibc_use_wasip2\n#define __wasilibc_use_wasip2\n#endif\n' \
+        > $SYSROOT_INC/__wasi_snapshot.h
+fi