diff --git a/unix/Makefile b/unix/Makefile
index 590264a927c4335e02f92ab2faa846db681a1adb..28ff910e5860ec6bd4a0d2408b7cc13d804cfba5 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -245,6 +245,7 @@ coverage:
 	    -Wold-style-definition -Wpointer-arith -Wshadow -Wuninitialized -Wunused-parameter \
 	    -DMICROPY_UNIX_COVERAGE' \
 	    LDFLAGS_EXTRA='-fprofile-arcs -ftest-coverage' \
+	    FROZEN_DIR=coverage-frzstr FROZEN_MPY_DIR=coverage-frzmpy \
 	    BUILD=build-coverage PROG=micropython_coverage
 
 coverage_test: coverage
diff --git a/unix/coverage-frzmpy/frzmpy1.py b/unix/coverage-frzmpy/frzmpy1.py
new file mode 100644
index 0000000000000000000000000000000000000000..8ad0f157302059013c97fa35afdb055ec3c223f5
--- /dev/null
+++ b/unix/coverage-frzmpy/frzmpy1.py
@@ -0,0 +1 @@
+print('frzmpy1')
diff --git a/unix/coverage-frzstr/frzstr1.py b/unix/coverage-frzstr/frzstr1.py
new file mode 100644
index 0000000000000000000000000000000000000000..6e88ac38d2cde8db9b6b388d2a16d2eefbb31bcc
--- /dev/null
+++ b/unix/coverage-frzstr/frzstr1.py
@@ -0,0 +1 @@
+print('frzstr1')