diff --git a/.travis.yml b/.travis.yml
index 5a73c07..f9586d0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,14 +20,6 @@ env:
     # Supply more than one RACKET_VERSION (as in the example below) to
     # create a Travis-CI build matrix to test against multiple Racket
     # versions.
-    - RACKET_VERSION=6.0
-    - RACKET_VERSION=6.1
-    - RACKET_VERSION=6.1.1
-    - RACKET_VERSION=6.2
-    - RACKET_VERSION=6.3
-    - RACKET_VERSION=6.4
-    - RACKET_VERSION=6.5
-    - RACKET_VERSION=6.6
     - RACKET_VERSION=6.7
     - RACKET_VERSION=HEAD
 
@@ -50,8 +42,8 @@ before_script:
 # `raco pkg install --deps search-auto` to install any required
 # packages without it getting stuck on a confirmation prompt.
 script:
- - raco test -x -p tr-immutable
- - if test $RACKET_VERSION != 6.0 -a $RACKET_VERSION != 6.1; then raco setup --check-pkg-deps --pkgs tr-immutable; fi
+ - raco test -p tr-immutable
+ - raco setup --check-pkg-deps --pkgs tr-immutable
  - raco pkg install --deps search-auto doc-coverage
  - raco doc-coverage tr-immutable
  - raco pkg install --deps search-auto cover cover-codecov