diff --git a/.evergreen/config.yml b/.evergreen/config.yml
index 2cfa886f42..67d7a2e5a4 100644
--- a/.evergreen/config.yml
+++ b/.evergreen/config.yml
@@ -94,7 +94,7 @@ functions:
           go version
           go env
 
-          LIBMONGOCRYPT_TAG="1.5.2"
+          LIBMONGOCRYPT_BRANCH="r1.5"
           # LIBMONGOCRYPT_COMMIT is the commit on libmongocrypt for the tag LIBMONGOCRYPT_TAG.
           LIBMONGOCRYPT_COMMIT="8f8675fa11922f00a4516a7f8a60621aa1ca1550"
           # Install libmongocrypt based on OS.
@@ -105,7 +105,7 @@ functions:
              mkdir libmongocrypt-all
              cd libmongocrypt-all
              # The following URL is published from the upload-all task in the libmongocrypt Evergreen project.
-             curl https://mciuploads.s3.amazonaws.com/libmongocrypt/all/master/$LIBMONGOCRYPT_COMMIT/libmongocrypt-all.tar.gz -o libmongocrypt-all.tar.gz
+             curl https://mciuploads.s3.amazonaws.com/libmongocrypt/all/$LIBMONGOCRYPT_BRANCH/$LIBMONGOCRYPT_COMMIT/libmongocrypt-all.tar.gz -o libmongocrypt-all.tar.gz
              tar -xf libmongocrypt-all.tar.gz
              cd ..
              cp libmongocrypt-all/windows-test/bin/mongocrypt.dll c:/libmongocrypt/bin
@@ -120,7 +120,7 @@ functions:
              mkdir libmongocrypt-all
              cd libmongocrypt-all
              # The following URL is published from the upload-all task in the libmongocrypt Evergreen project.
-             curl https://mciuploads.s3.amazonaws.com/libmongocrypt/all/master/$LIBMONGOCRYPT_COMMIT/libmongocrypt-all.tar.gz -o libmongocrypt-all.tar.gz
+             curl https://mciuploads.s3.amazonaws.com/libmongocrypt/all/$LIBMONGOCRYPT_BRANCH/$LIBMONGOCRYPT_COMMIT/libmongocrypt-all.tar.gz -o libmongocrypt-all.tar.gz
              tar -xf libmongocrypt-all.tar.gz
              cd ..
              mv libmongocrypt-all/macos/include ./install/libmongocrypt