diff --git a/src/PIL/ImageFont.py b/src/PIL/ImageFont.py
index 7074a70c0..f43f95b9a 100644
--- a/src/PIL/ImageFont.py
+++ b/src/PIL/ImageFont.py
@@ -545,6 +545,8 @@ def truetype(font=None, size=10, index=0, encoding="", layout_engine=None):
     try:
         return freetype(font)
     except IOError:
+        if not isPath(font):
+            raise
         ttf_filename = os.path.basename(font)
 
         dirs = []