diff --git a/repl/test-repl-darwin.py b/repl/test-repl-darwin.py
index a7046b4..85c155c 100644
--- a/repl/test-repl-darwin.py
+++ b/repl/test-repl-darwin.py
@@ -6,7 +6,7 @@
 #
 # RUN: rm -rf %t.dir
 # RUN: mkdir %t.dir
-# RUN: python %s %{swift} > %t.dir/output.txt
+# RUN: %{python} %s %{swift} > %t.dir/output.txt
 # RUN: %{FileCheck} --input-file %t.dir/output.txt %s
 # CHECK: OK
 
diff --git a/repl/test-repl-glibc.py b/repl/test-repl-glibc.py
index 15fdcb2..d9f57a5 100644
--- a/repl/test-repl-glibc.py
+++ b/repl/test-repl-glibc.py
@@ -5,7 +5,7 @@
 #
 # RUN: rm -rf %t.dir
 # RUN: mkdir %t.dir
-# RUN: python %s %{swift} > %t.dir/output.txt
+# RUN: %{python} %s %{swift} > %t.dir/output.txt
 # RUN: %{FileCheck} --input-file %t.dir/output.txt %s
 # CHECK: OK