diff --git a/README.md b/README.md
index e982d005d..18a0335a3 100644
--- a/README.md
+++ b/README.md
@@ -45,7 +45,7 @@ P. Kent _et al._ J. Chem. Phys. **152** 174105 (2020), https://doi.org/10.1063/5
 # Installation Prerequisites
 
  * C++ 17 and C99 capable compilers. 
- * CMake v3.17.0 or later, build utility, http://www.cmake.org
+ * CMake v3.21.0 or later, build utility, http://www.cmake.org
  * BLAS/LAPACK, numerical library. Use vendor and platform-optimized libraries.
  * LibXml2, XML parser, http://xmlsoft.org/
  * HDF5 v1.10.0 or later, portable I/O library, http://www.hdfgroup.org/HDF5/
diff --git a/docs/installation.rst b/docs/installation.rst
index d8ecf9977..d87ca9bb0 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -186,7 +186,7 @@ Building with CMake
 The build system for QMCPACK is based on CMake. It will autoconfigure
 based on the detected compilers and libraries. The most recent version
 of CMake has the best detection for the greatest variety of systems. The
-minimum required version of CMake is 3.17.0. Most
+minimum required version of CMake is 3.21.0. Most
 computer installations have a sufficiently recent CMake, though it might
 not be the default.