diff --git a/.travis.yml b/.travis.yml
index 20fa9beeb..a6e1a99ea 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -54,7 +54,10 @@ matrix:
     - name: Trusty (clang-3.8 + MSan + Test Zstd)
       script:
         - make clang38install
-        - CC=clang-3.8 make clean msan-test-zstd
+        # External libraries must be turned off when using MSAN tests,
+        # because they are not msan-instrumented,
+        # so any data coming from these libraries is always considered "uninitialized"
+        - CC=clang-3.8 make clean msan-test-zstd HAVE_ZLIB=0 HAVE_LZ4=0 HAVE_LZMA=0
 
     - name: Trusty (Minimal Decompressor Macros)
       script: