diff --git a/INSTALL.md b/INSTALL.md
index cfcaefaa06..9f71cd221a 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -75,7 +75,7 @@ Optional prerequisites:
     - [blacspp](https://github.com/wavefunction91/blacspp.git) -- a modern C++ (C++17) wrapper for BLACS
 - Python3 interpreter -- to test (optionally-built) Python bindings
 - [Range-V3](https://github.com/ericniebler/range-v3.git) -- a Ranges library that served as the basis for Ranges component of C++20; only used for some unit testing of the functionality anticipated to be supported by future C++ standards.
-- [TTG](https://github.com/TESSEorg/ttg.git) -- C++ implementation of the Template Task Graph programming model for fine-grained flow-graph composition of distributed memory programs (tag 4643df546d52481c7ad4bf5b7cce45289dc6b222).
+- [TTG](https://github.com/TESSEorg/ttg.git) -- C++ implementation of the Template Task Graph programming model for fine-grained flow-graph composition of distributed memory programs (tag 18ecba5ddfa2953698642d75ec509a0735e0cd3e).
 
 Many of these dependencies can be installed with a package manager,
 such as Homebrew on OS X or apt-get on Debian Linux distributions;
diff --git a/external/versions.cmake b/external/versions.cmake
index 9aa1db064a..0e68e87eb2 100644
--- a/external/versions.cmake
+++ b/external/versions.cmake
@@ -40,5 +40,5 @@ set(TA_TRACKED_RANGEV3_TAG 2e0591c57fce2aca6073ad6e4fdc50d841827864)
 set(TA_TRACKED_RANGEV3_PREVIOUS_TAG dbdaa247a25a0daa24c68f1286a5693c72ea0006)
 
 set(TA_TRACKED_TTG_URL https://github.com/TESSEorg/ttg)
-set(TA_TRACKED_TTG_TAG 4643df546d52481c7ad4bf5b7cce45289dc6b222)
-set(TA_TRACKED_TTG_PREVIOUS_TAG 0adff52aa1ebdad013ab3843a7a68c2bb06b60a8)
+set(TA_TRACKED_TTG_TAG 18ecba5ddfa2953698642d75ec509a0735e0cd3e)
+set(TA_TRACKED_TTG_PREVIOUS_TAG 4643df546d52481c7ad4bf5b7cce45289dc6b222)