diff --git a/var/spack/repos/builtin/packages/proj/package.py b/var/spack/repos/builtin/packages/proj/package.py
index ef18d834dc..633ca182f8 100644
--- a/var/spack/repos/builtin/packages/proj/package.py
+++ b/var/spack/repos/builtin/packages/proj/package.py
@@ -92,6 +92,11 @@ class Proj(CMakePackage, AutotoolsPackage):
 
     # https://proj.org/install.html#build-requirements
     with when("build_system=cmake"):
+        # CMake 3.19 refactored the FindTiff module interface, update older proj's
+        # to be compatible with this "new" interface
+        # patch replaces the TIFF_LIBRARY variable (no longer used) with TIFF_LIBRARIES
+        patch("proj-8.1-cmake-3.29-new-tiff-interface.patch", when="+tiff @:9.1.0 ^cmake@3.19:")
+        conflicts("cmake@3.19:", when="@:7")
         depends_on("cmake@3.9:", when="@6:", type="build")
         depends_on("cmake@3.5:", when="@5", type="build")
         depends_on("cmake@2.6:", when="@:4", type="build")
diff --git a/var/spack/repos/builtin/packages/proj/proj-8.1-cmake-3.29-new-tiff-interface.patch b/var/spack/repos/builtin/packages/proj/proj-8.1-cmake-3.29-new-tiff-interface.patch
new file mode 100644
index 0000000000..d278029aed
--- /dev/null
+++ b/var/spack/repos/builtin/packages/proj/proj-8.1-cmake-3.29-new-tiff-interface.patch
@@ -0,0 +1,13 @@
+diff --git a/src/lib_proj.cmake b/src/lib_proj.cmake
+index f2de1c10..a5697608 100644
+--- a/src/lib_proj.cmake
++++ b/src/lib_proj.cmake
+@@ -405,7 +405,7 @@ endif()
+ if(TIFF_ENABLED)
+   target_compile_definitions(proj PRIVATE -DTIFF_ENABLED)
+   target_include_directories(proj PRIVATE ${TIFF_INCLUDE_DIR})
+-  target_link_libraries(proj PRIVATE ${TIFF_LIBRARY})
++  target_link_libraries(proj PRIVATE ${TIFF_LIBRARIES})
+ endif()
+ 
+ if(CURL_ENABLED)