--- a/cargo-afl-common/src/lib.rs
+++ b/cargo-afl-common/src/lib.rs
@@ -64,11 +64,17 @@ fn pkg_version() -> String {
 }

 pub fn afl_dir() -> Result<PathBuf> {
-    data_dir("afl")
+    if let Ok(val) = env::var("CARGO_AFL_DIR") {
+        return Ok(PathBuf::from(val));
+    }
+    data_dir("afl")
 }

 pub fn afl_llvm_dir() -> Result<PathBuf> {
-    data_dir("afl-llvm")
+    if let Ok(val) = env::var("CARGO_AFL_LLVM_DIR") {
+        return Ok(PathBuf::from(val));
+    }
+    data_dir("afl-llvm")
 }

 pub fn object_file_path() -> Result<PathBuf> {