diff --git a/snakehouse/requirements.py b/snakehouse/requirements.py
index e4bea2af66f45c1236ee4f6b7c9c43478d04717e..a5df28a9c3a77bd70ff6d75aeb640b3f83649bf2 100644
--- a/snakehouse/requirements.py
+++ b/snakehouse/requirements.py
@@ -11,7 +11,7 @@ def find_pyx(directory_path: str) -> tp.List[str]:
     :param directory_path: directory to look through
     :return: .pyx files found
     """
-    return find_files(directory_path, r'(.*)\.pyx', scan_subdirectories=True)
+    return find_files(directory_path, '(.*)\\.pyx$', scan_subdirectories=True)
 
 
 @for_argument(returns=list)
@@ -22,7 +22,7 @@ def find_c(directory_path: str) -> tp.List[str]:
     :param directory_path: directory to look through
     :return: .c files found
     """
-    return find_files(directory_path, r'(.*)\.c', scan_subdirectories=True)
+    return find_files(directory_path, '(.*)\\.c$', scan_subdirectories=True)
 
 
 def find_pyx_and_c(directory_path: str) -> tp.List[str]: