diff --git a/aspect/testing/tests/src/com/google/idea/blaze/aspect/cpp/coptsmakevars/CoptsMakeVarsTest.java b/aspect/testing/tests/src/com/google/idea/blaze/aspect/cpp/coptsmakevars/CoptsMakeVarsTest.java
index db3e69db4a1..009ee245e53 100644
--- a/aspect/testing/tests/src/com/google/idea/blaze/aspect/cpp/coptsmakevars/CoptsMakeVarsTest.java
+++ b/aspect/testing/tests/src/com/google/idea/blaze/aspect/cpp/coptsmakevars/CoptsMakeVarsTest.java
@@ -42,7 +42,7 @@ public void testCoptsPrefinedMakeVars() throws Exception {
     assertThat(cTargetIdeInfo.getTargetCoptList()).hasSize(2);
     // These predefined variables' values are dependent on build system and configuration.
     assertThat(cTargetIdeInfo.getTargetCoptList().get(0))
-        .containsMatch("^-DPREFINED_BINDIR=(blaze|bazel)-out/[-0-9a-z]+/bin$");
+        .containsMatch("^-DPREFINED_BINDIR=(blaze|bazel)-out/[0-9a-z_-]+/bin$");
     assertThat(cTargetIdeInfo.getTargetCoptList().get(1)).isEqualTo("-DPREFINED_BINDIR2=$(BINDIR)");
   }
 }