diff --git a/src/tools/compiletest/src/header.rs b/src/tools/compiletest/src/header.rs
index ccce62bd5b0cf..89df2b54de38d 100644
--- a/src/tools/compiletest/src/header.rs
+++ b/src/tools/compiletest/src/header.rs
@@ -90,6 +90,9 @@ pub struct TestProps {
     pub unset_rustc_env: Vec<String>,
     // Environment settings to use during execution
     pub exec_env: Vec<(String, String)>,
+    // Environment variables to unset prior to execution.
+    // Variables are unset before applying 'exec_env'
+    pub unset_exec_env: Vec<String>,
     // Build documentation for all specified aux-builds as well
     pub build_aux_docs: bool,
     // Flag to force a crate to be built with the host architecture
@@ -198,6 +201,7 @@ mod directives {
     pub const AUX_CRATE: &'static str = "aux-crate";
     pub const EXEC_ENV: &'static str = "exec-env";
     pub const RUSTC_ENV: &'static str = "rustc-env";
+    pub const UNSET_EXEC_ENV: &'static str = "unset-exec-env";
     pub const UNSET_RUSTC_ENV: &'static str = "unset-rustc-env";
     pub const FORBID_OUTPUT: &'static str = "forbid-output";
     pub const CHECK_TEST_LINE_NUMBERS_MATCH: &'static str = "check-test-line-numbers-match";
@@ -231,6 +235,7 @@ impl TestProps {
             rustc_env: vec![],
             unset_rustc_env: vec![],
             exec_env: vec![],
+            unset_exec_env: vec![],
             build_aux_docs: false,
             force_host: false,
             check_stdout: false,
@@ -382,6 +387,12 @@ impl TestProps {
                     &mut self.exec_env,
                     Config::parse_env,
                 );
+                config.push_name_value_directive(
+                    ln,
+                    UNSET_EXEC_ENV,
+                    &mut self.unset_exec_env,
+                    |r| r,
+                );
                 config.push_name_value_directive(
                     ln,
                     RUSTC_ENV,
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index f6597c729387e..e88074961a683 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -1613,8 +1613,13 @@ impl<'test> TestCx<'test> {
                 test_client
                     .args(&["run", &support_libs.len().to_string(), &prog])
                     .args(support_libs)
-                    .args(args)
-                    .envs(env.clone());
+                    .args(args);
+
+                for key in &self.props.unset_exec_env {
+                    test_client.env_remove(key);
+                }
+                test_client.envs(env.clone());
+
                 self.compose_and_run(
                     test_client,
                     self.config.run_lib_path.to_str().unwrap(),
@@ -1626,7 +1631,13 @@ impl<'test> TestCx<'test> {
                 let aux_dir = self.aux_output_dir_name();
                 let ProcArgs { prog, args } = self.make_run_args();
                 let mut wr_run = Command::new("wr-run");
-                wr_run.args(&[&prog]).args(args).envs(env.clone());
+                wr_run.args(&[&prog]).args(args);
+
+                for key in &self.props.unset_exec_env {
+                    wr_run.env_remove(key);
+                }
+                wr_run.envs(env.clone());
+
                 self.compose_and_run(
                     wr_run,
                     self.config.run_lib_path.to_str().unwrap(),
@@ -1638,7 +1649,13 @@ impl<'test> TestCx<'test> {
                 let aux_dir = self.aux_output_dir_name();
                 let ProcArgs { prog, args } = self.make_run_args();
                 let mut program = Command::new(&prog);
-                program.args(args).current_dir(&self.output_base_dir()).envs(env.clone());
+                program.args(args).current_dir(&self.output_base_dir());
+
+                for key in &self.props.unset_exec_env {
+                    program.env_remove(key);
+                }
+                program.envs(env.clone());
+
                 self.compose_and_run(
                     program,
                     self.config.run_lib_path.to_str().unwrap(),