diff --git a/icu4c/source/Makefile.in b/icu4c/source/Makefile.in
index 4d67422e4ce..fa94c48449c 100644
--- a/icu4c/source/Makefile.in
+++ b/icu4c/source/Makefile.in
@@ -316,7 +316,7 @@ icu4j-data-install icu4j-data: all tests
 
 # For updating Windows makefiles
 
-WINDOWS_UPDATEFILES=$(srcdir)/data/makedata.mak $(shell find $(srcdir) -name '*.vcproj')
+WINDOWS_UPDATEFILES=$(srcdir)/data/makedata.mak $(shell find $(srcdir) -name '*.vcproj' -o -name '*.vcxproj')
 
 WINDOWS_UPDATEFILES_SED=config/windows-update.sed