diff --git a/ports/icu/fix-using-install-sh.diff b/ports/icu/fix-using-install-sh.diff
new file mode 100644
index 00000000000000..43a86dea5aa45a
--- /dev/null
+++ b/ports/icu/fix-using-install-sh.diff
@@ -0,0 +1,39 @@
+diff --git a/source/Makefile.in b/source/Makefile.in
+index 9e15b6a016..53330a3921 100644
+--- a/source/Makefile.in
++++ b/source/Makefile.in
+@@ -189,7 +189,10 @@ install-icu: $(INSTALLED_BUILT_FILES)
+ 	$(INSTALL_SCRIPT) $(top_srcdir)/mkinstalldirs $(DESTDIR)$(pkgdatadir)/mkinstalldirs
+ 	$(INSTALL_SCRIPT) $(top_srcdir)/install-sh $(DESTDIR)$(pkgdatadir)/install-sh
+ 	@$(MKINSTALLDIRS) $(DESTDIR)$(libdir)/pkgconfig
+-	$(INSTALL_DATA) $(ALL_PKGCONFIG_FILES) $(DESTDIR)$(libdir)/pkgconfig/
++	# icu's fallback install-sh does not support multi-file install
++	@for file in $(ALL_PKGCONFIG_FILES); do \
++	  $(INSTALL_DATA) "$${file}" $(DESTDIR)$(libdir)/pkgconfig/ ; \
++	done
+ 	$(INSTALL_DATA) $(top_srcdir)/../LICENSE $(DESTDIR)$(pkgdatadir)/LICENSE
+ ifeq ($(INSTALL_ICU_CONFIG),true)
+ 	$(INSTALL_SCRIPT) $(top_builddir)/config/icu-config $(DESTDIR)$(bindir)/icu-config
+diff --git a/source/configure b/source/configure
+index dfa3a091f8..8ee911d42d 100755
+--- a/source/configure
++++ b/source/configure
+@@ -4935,12 +4935,12 @@ test -z "$INSTALL_DATA" && INSTALL_DATA='${INSTALL} -m 644'
+ 
+ 
+ 
+-# make sure install is relative to srcdir - if a script
+-if test "$srcdir" = "."; then
+-  # If srcdir isn't just ., then (srcdir) is already prepended.
+-  if test "${ac_install_sh}" = "${INSTALL}"; then
+-   INSTALL="\\\$(top_srcdir)/${ac_install_sh}"
+-  fi
++# If using the included install-sh, make INSTALL work from any build dir.
++if test "${ac_install_sh}" = "${INSTALL}"; then
++    case "$srcdir" in
++        .|./*|../*)  INSTALL="\\\$(top_builddir)/${ac_install_sh}" ;;
++        *) ;;
++    esac
+ fi
+ 
+ # TODO(ICU-20301): Remove fallback to Python 2.
diff --git a/ports/icu/portfile.cmake b/ports/icu/portfile.cmake
index a1aaeee59c7ec7..67e37f03342bd0 100644
--- a/ports/icu/portfile.cmake
+++ b/ports/icu/portfile.cmake
@@ -12,6 +12,7 @@ vcpkg_extract_source_archive(SOURCE_PATH
         fix_bsd_and_solaris.patch
         fix_parallel_build_on_windows.patch
         fix-python-path-with-spaces.patch
+        fix-using-install-sh.diff
         mh-darwin.patch
         mh-mingw.patch
         mh-msys-msvc.patch
diff --git a/ports/icu/vcpkg.json b/ports/icu/vcpkg.json
index 098e7c84b8836d..d296c30bb18872 100644
--- a/ports/icu/vcpkg.json
+++ b/ports/icu/vcpkg.json
@@ -1,7 +1,7 @@
 {
   "name": "icu",
   "version": "78.3",
-  "port-version": 1,
+  "port-version": 2,
   "description": "Mature and widely used Unicode and localization library.",
   "homepage": "https://icu.unicode.org/home",
   "license": "ICU",
diff --git a/versions/baseline.json b/versions/baseline.json
index e10984dfb7a070..5eeaef1449a300 100644
--- a/versions/baseline.json
+++ b/versions/baseline.json
@@ -3942,7 +3942,7 @@
     },
     "icu": {
       "baseline": "78.3",
-      "port-version": 1
+      "port-version": 2
     },
     "ideep": {
       "baseline": "2026-05-11",
diff --git a/versions/i-/icu.json b/versions/i-/icu.json
index c93d766f222bc6..e149b64df5aa5f 100644
--- a/versions/i-/icu.json
+++ b/versions/i-/icu.json
@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "50a263a104075be2c5647af8e723a18914f6ee13",
+      "version": "78.3",
+      "port-version": 2
+    },
     {
       "git-tree": "931a42f3b3b911ba73dbbaead4c1e0037a158efd",
       "version": "78.3",