diff --git a/Makefile.am b/Makefile.am
index 160df28..aad6130 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -6,10 +6,17 @@ AM_CPPFLAGS = -I$(top_srcdir)/include
 AM_CFLAGS = @VLIBC_CFLAGS@
 
 # ---- Library -------------------------------------------------------------
-vlibc_include_HEADERS = include/vlibc.h
+vlibc_include_HEADERS = include/vlibc.h include/stddef.h include/string.h
 vlibc_lib_LTLIBRARIES = libvlibc.la
 
-libvlibc_la_SOURCES = src/vlibc.c
+libvlibc_la_SOURCES = src/vlibc.c src/string/strlen.c src/string/strcmp.c \
+    src/string/memcpy.c src/string/memmove.c src/string/memset.c
+if PROFILE_GE_2
+libvlibc_la_SOURCES += src/string/strlcpy.c src/string/strlcat.c
+endif
+if PROFILE_GE_3
+libvlibc_la_SOURCES += src/string/strcasestr.c
+endif
 libvlibc_la_LDFLAGS = -version-info 0:0:0 -no-undefined
 
 # Install location depends on the install method (see configure.ac).
@@ -21,6 +28,13 @@ vlibc_includedir = $(prefix)/lib/vlibc/include
 vlibc_libdir = $(prefix)/lib/vlibc/lib
 endif
 
+# Generated per-profile feature header (see configure.ac); installed under
+# $(vlibc_includedir)/vlibc/. A dedicated primary is used because
+# nodist_nobase_vlibc_include_HEADERS is rejected by automake (the "nobase"
+# prefix is unsupported for this directory) and loses the vlibc/ path.
+vlibc_featuresdir = $(vlibc_includedir)/vlibc
+nodist_vlibc_features_HEADERS = include/vlibc/features.h
+
 # ---- Compiler drivers ----------------------------------------------------
 bin_SCRIPTS = tools/vlibc-gcc tools/vlibc-clang
 
diff --git a/configure b/configure
index 55fcbc1..754a2d2 100755
--- a/configure
+++ b/configure
@@ -679,6 +679,10 @@ MUSL_CC
 vlibc_install_mode
 INSTALL_OVERWRITE_FALSE
 INSTALL_OVERWRITE_TRUE
+PROFILE_GE_3_FALSE
+PROFILE_GE_3_TRUE
+PROFILE_GE_2_FALSE
+PROFILE_GE_2_TRUE
 vlibc_level
 vlibc_profile
 VLIBC_CFLAGS
@@ -5285,6 +5289,23 @@ esac
 
 
 
+ if test "$vlibc_level" -ge 2; then
+  PROFILE_GE_2_TRUE=
+  PROFILE_GE_2_FALSE='#'
+else
+  PROFILE_GE_2_TRUE='#'
+  PROFILE_GE_2_FALSE=
+fi
+
+ if test "$vlibc_level" -ge 3; then
+  PROFILE_GE_3_TRUE=
+  PROFILE_GE_3_FALSE='#'
+else
+  PROFILE_GE_3_TRUE='#'
+  PROFILE_GE_3_FALSE=
+fi
+
+
 # ---- Install method ------------------------------------------------------
 # "alongside" installs vlibc next to the system libc: headers and libraries go
 # under a vlibc-specific tree, used via the vlibc-gcc / vlibc-clang drivers.
@@ -14586,6 +14607,14 @@ if test -z "${am__fastdepCC_TRUE}" && test -z "${am__fastdepCC_FALSE}"; then
   as_fn_error $? "conditional \"am__fastdepCC\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
 fi
+if test -z "${PROFILE_GE_2_TRUE}" && test -z "${PROFILE_GE_2_FALSE}"; then
+  as_fn_error $? "conditional \"PROFILE_GE_2\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
+if test -z "${PROFILE_GE_3_TRUE}" && test -z "${PROFILE_GE_3_FALSE}"; then
+  as_fn_error $? "conditional \"PROFILE_GE_3\" was never defined.
+Usually this means the macro was only invoked conditionally." "$LINENO" 5
+fi
 if test -z "${INSTALL_OVERWRITE_TRUE}" && test -z "${INSTALL_OVERWRITE_FALSE}"; then
   as_fn_error $? "conditional \"INSTALL_OVERWRITE\" was never defined.
 Usually this means the macro was only invoked conditionally." "$LINENO" 5
diff --git a/configure.ac b/configure.ac
index fc3c996..9bbf7dc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -118,6 +118,9 @@ AS_CASE([$vlibc_profile],
 AC_SUBST([vlibc_profile])
 AC_SUBST([vlibc_level])
 
+AM_CONDITIONAL([PROFILE_GE_2], [test "$vlibc_level" -ge 2])
+AM_CONDITIONAL([PROFILE_GE_3], [test "$vlibc_level" -ge 3])
+
 # ---- Install method ------------------------------------------------------
 # "alongside" installs vlibc next to the system libc: headers and libraries go
 # under a vlibc-specific tree, used via the vlibc-gcc / vlibc-clang drivers.