diff --git a/loopy/kernel.py b/loopy/kernel.py
index d68fb938a74472b11fd8c3dc229931d580f2a7af..33d4171e217aa6205e77d6ba1ea8494a2369f22b 100644
--- a/loopy/kernel.py
+++ b/loopy/kernel.py
@@ -913,12 +913,13 @@ class LoopKernel(Record):
                         % type(insn))
 
             for insn in insn.split("\n"):
-                insn = insn.strip()
+                comment_start = insn.find("#")
+                if comment_start >= 0:
+                    insn = insn[:comment_start]
 
+                insn = insn.strip()
                 if not insn:
                     continue
-                if insn.startswith("#"):
-                    continue
 
                 for sub_insn in expand_defines(insn, defines, single_valued=False):
                     parse_insn(sub_insn)