diff --git a/debian/changelog b/debian/changelog
index 28fcf782..d9924ab2 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -4,6 +4,8 @@ llvm-toolchain-snapshot (1:18~++20230921012857+4cf8da94198d-1~exp1) UNRELEASED;
     to follow upstream change b7ff03206d668cd5a620a9d4e1b22ea112ed56e3
     And disable generation of the doc on old distro
   * Also install readtapi => llvm-readtapi symlink
+  * When building flang, add -DLLVM_INSTALL_GTEST=On.
+    See https://reviews.llvm.org/D154869
 
  -- Sylvestre Ledru <sylvestre@debian.org>  Mon, 25 Sep 2023 21:51:52 +0200
 
diff --git a/debian/rules b/debian/rules
index 6a38075b..faaae018 100755
--- a/debian/rules
+++ b/debian/rules
@@ -289,6 +289,7 @@ endif
 # flang is only for 64bits
 ifneq (,$(filter flang-$(LLVM_VERSION), $(shell dh_listpackages)))
     PROJECTS += ;flang
+    STAGE_ALL_CMAKE_EXTRA += -DLLVM_INSTALL_GTEST=On
 endif
 
 CODECOVERAGE=no