diff --git a/.gitignore b/.gitignore
index 0f4b63115..8c797335d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,6 +18,7 @@ idris2docs_venv
 /ipkg/build
 
 /tests/**/build
+/tests/**/prefix
 /tests/**/output*
 /tests/**/*.so
 /tests/**/*.dylib
diff --git a/tests/idris2/pkg/pkg010/run b/tests/idris2/pkg/pkg010/run
index 1135ebaaa..1a4d91f79 100755
--- a/tests/idris2/pkg/pkg010/run
+++ b/tests/idris2/pkg/pkg010/run
@@ -1,6 +1,5 @@
 . ../../../testutils.sh
 
-export IDRIS2_PACKAGE_PATH=$IDRIS2_PREFIX/$NAME_VERSION
 export IDRIS2_PREFIX=$test_dir/currently/nonexistent/dir/
 
 export IDRIS2_INC_CGS=
diff --git a/tests/idris2/pkg/pkg016/run b/tests/idris2/pkg/pkg016/run
index 7b26a4531..367a8ff68 100644
--- a/tests/idris2/pkg/pkg016/run
+++ b/tests/idris2/pkg/pkg016/run
@@ -6,7 +6,3 @@ idris2 --install baz.ipkg > /dev/null
 idris2 --build test.ipkg
 
 build/exec/test
-
-rm -r "${IDRIS2_PREFIX}"/idris2-*/foo-0
-rm -r "${IDRIS2_PREFIX}"/idris2-*/bar-0
-rm -r "${IDRIS2_PREFIX}"/idris2-*/baz-0
diff --git a/tests/testutils.sh b/tests/testutils.sh
index 6dcb4179b..7f64eb64f 100755
--- a/tests/testutils.sh
+++ b/tests/testutils.sh
@@ -9,6 +9,7 @@ idris2="$1"
 # Delete build files between runs to prevent unexpected differences.
 # As this is at the top-level, this is run when this script is imported.
 rm -rf build
+rm -rf prefix
 
 idris2() {
     $idris2 --no-banner --console-width 0 --no-color "$@"
@@ -32,8 +33,30 @@ sed_literal() {
 # Folder containing the currently running test
 if [ "$OS" = "windows" ]; then
     test_dir="$(cygpath -m "$(pwd)")"
+    SEP=";"
 else
     test_dir="$(pwd)"
+    SEP=":"
+fi
+
+# Set variables for hygiene testing
+if [ -z "$PREFIX_CHANGED" ] && [ -n "$IDRIS2_PREFIX" ]; then
+    OLD_PREFIX="$IDRIS2_PREFIX"
+    NEW_PREFIX="$test_dir/prefix"
+
+    OLD_PP="$OLD_PREFIX/$NAME_VERSION"
+    NEW_PP="$NEW_PREFIX/$NAME_VERSION"
+
+    # Set where to look to installed stuff
+    export IDRIS2_PACKAGE_PATH="$OLD_PP$SEP$NEW_PP"
+    export IDRIS2_LIBS="$OLD_PP/libs$SEP$NEW_PP/libs"
+    export IDRIS2_DATA="$OLD_PP/support$SEP$NEW_PP/support"
+
+    # Set where to install stuff
+    export IDRIS2_PREFIX="$NEW_PREFIX"
+
+    # Save from re-sourcing this file several times
+    export PREFIX_CHANGED=1
 fi
 
 # Remove test directory from output