diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 20922c5..924d0c2 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -2,6 +2,29 @@
 
 ---
 
+## V43 2026-03-21 01:15:00
+
+**Add zlib build to chroot phase — ld needs libz.so.1 at runtime**
+
+### Changes:
+- Added `024a-zlib.sh`: Builds zlib as the first package in the chroot. The linker
+  (`ld`) from binutils pass 2 was compiled with zlib support and dynamically links
+  against `libz.so.1`. Without it, every link attempt fails with "error while loading
+  shared libraries: libz.so.1: cannot open shared object file". This was the actual
+  root cause of "C compiler cannot create executables" — not a missing ld symlink
+  (though that was also needed and fixed in V42).
+- Updated `023a-chroot-build-all.sh`: Added `024a-zlib.sh` between 024 and 025.
+- Simplified `024-chroot-essentials.sh`: Replaced verbose gcc diagnostic with a
+  simple presence check + note that zlib must be built first.
+
+### Plan deviation/changes:
+- None
+
+### What is missing/needs polish:
+- None
+
+---
+
 ## V42 2026-03-21 01:00:00
 
 **Fix chroot gcc linker failure — create cross-prefix symlinks for ld**
diff --git a/toolchain/scripts/023a-chroot-build-all.sh b/toolchain/scripts/023a-chroot-build-all.sh
index 5104b01..792bca1 100644
--- a/toolchain/scripts/023a-chroot-build-all.sh
+++ b/toolchain/scripts/023a-chroot-build-all.sh
@@ -75,6 +75,7 @@ echo "=== Chapter 7: Chroot Build Scripts ==="
 echo ""
 
 run_script "${SCRIPTS}/024-chroot-essentials.sh"
+run_script "${SCRIPTS}/024a-zlib.sh"
 run_script "${SCRIPTS}/025-gettext.sh"
 run_script "${SCRIPTS}/026-bison.sh"
 run_script "${SCRIPTS}/027-perl.sh"
diff --git a/toolchain/scripts/024-chroot-essentials.sh b/toolchain/scripts/024-chroot-essentials.sh
index 306588a..6ceb0e1 100755
--- a/toolchain/scripts/024-chroot-essentials.sh
+++ b/toolchain/scripts/024-chroot-essentials.sh
@@ -83,53 +83,13 @@ install -o root -g utmp -m 664 /dev/null /var/log/wtmp
 
 echo "=== Essential files and symlinks created ==="
 echo ""
-
-# --- Verify compiler works inside chroot --------------------------------------
-echo ">>> Verifying gcc works inside chroot..."
+echo ">>> Checking gcc and ld are present..."
+echo "  gcc: $(ls /usr/bin/gcc 2>/dev/null && echo 'OK' || echo 'MISSING')"
+echo "  ld:  $(ls /usr/bin/ld 2>/dev/null && echo 'OK' || echo 'MISSING')"
+echo "  ld-linux-x86-64.so.2: $(ls /lib64/ld-linux-x86-64.so.2 2>/dev/null && echo 'OK' || echo 'MISSING')"
+echo "  crt1.o: $(ls /usr/lib/crt1.o 2>/dev/null && echo 'OK' || echo 'MISSING')"
 echo ""
-
-# Show where gcc is
-echo "  which gcc: $(which gcc 2>&1 || echo 'NOT FOUND')"
-echo "  which cc:  $(which cc 2>&1 || echo 'NOT FOUND')"
-echo "  which ld:  $(which ld 2>&1 || echo 'NOT FOUND')"
+echo "  NOTE: gcc won't link until zlib is built (ld needs libz.so.1)."
+echo "  024a-zlib.sh runs next to fix this."
 echo ""
-
-# Check for the dynamic linker
-if [ -e /lib64/ld-linux-x86-64.so.2 ]; then
-    echo "  /lib64/ld-linux-x86-64.so.2: EXISTS"
-    ls -la /lib64/ld-linux-x86-64.so.2
-else
-    echo "  WARNING: /lib64/ld-linux-x86-64.so.2 NOT FOUND"
-    echo "  Checking /usr/lib..."
-    ls -la /usr/lib/ld-linux-x86-64.so.2 2>/dev/null || echo "  /usr/lib/ld-linux-x86-64.so.2 NOT FOUND"
-    echo "  Contents of /lib64/:"
-    ls -la /lib64/ 2>/dev/null || echo "  /lib64 does not exist"
-fi
-echo ""
-
-# Check for crt files
-echo "  crt1.o: $(find /usr/lib -name crt1.o 2>/dev/null || echo 'NOT FOUND')"
-echo "  crti.o: $(find /usr/lib -name crti.o 2>/dev/null || echo 'NOT FOUND')"
-echo ""
-
-# Try to compile a test program
-echo "  Testing: echo 'int main(){}' | gcc -x c - -o /tmp/test-gcc"
-if echo 'int main(){}' | gcc -x c - -o /tmp/test-gcc 2>/tmp/gcc-test-error.log; then
-    echo "  PASS: gcc can create executables"
-    rm -f /tmp/test-gcc
-else
-    echo "  FAIL: gcc cannot create executables!"
-    echo "  Error output:"
-    cat /tmp/gcc-test-error.log
-    echo ""
-    echo "  Trying with verbose output:"
-    echo 'int main(){}' | gcc -v -x c - -o /tmp/test-gcc 2>&1 | tail -30
-    echo ""
-    echo "  gcc search dirs:"
-    gcc -print-search-dirs 2>&1 | head -10
-    exit 1
-fi
-rm -f /tmp/gcc-test-error.log
-
-echo ""
-echo "Next: Run the chroot build scripts (025-xxx) to build additional tools."
+echo "Next: Build zlib, then the remaining chroot tools."
diff --git a/toolchain/scripts/024a-zlib.sh b/toolchain/scripts/024a-zlib.sh
new file mode 100644
index 0000000..5ba7e52
--- /dev/null
+++ b/toolchain/scripts/024a-zlib.sh
@@ -0,0 +1,42 @@
+#!/bin/bash
+# ============================================================================
+# DarkForge Linux — Phase 0, Chapter 7: Zlib (Chroot)
+# ============================================================================
+# Purpose:  Build zlib inside the chroot. The binutils linker (ld) from pass 2
+#           was built with zlib support and dynamically links against libz.so.1.
+#           Without zlib installed, ld fails with:
+#             "error while loading shared libraries: libz.so.1"
+#           This must be the FIRST thing built in the chroot, before any
+#           package that needs to link (i.e., everything).
+# Inputs:   /sources/zlib-1.3.2.tar.xz
+# Outputs:  /usr/lib/libz.so.1
+# Assumes:  Running inside chroot
+# ============================================================================
+
+set -euo pipefail
+
+PACKAGE="zlib"
+VERSION="1.3.2"
+
+echo "=== Building ${PACKAGE}-${VERSION} (Chroot — ld dependency) ==="
+
+cd /sources
+tar -xf "${PACKAGE}-${VERSION}.tar.xz"
+cd "${PACKAGE}-${VERSION}"
+
+./configure --prefix=/usr
+
+make
+make install
+
+# Verify libz.so.1 exists
+if [ -f /usr/lib/libz.so.1 ]; then
+    echo "  PASS: /usr/lib/libz.so.1 exists"
+else
+    echo "  FAIL: /usr/lib/libz.so.1 NOT FOUND after install!"
+    exit 1
+fi
+
+cd /sources
+rm -rf "${PACKAGE}-${VERSION}"
+echo "=== ${PACKAGE}-${VERSION} complete ==="