diff --git a/lib/assert.h b/lib/assert.h
index d7e2512..ddf316b 100644
--- a/lib/assert.h
+++ b/lib/assert.h
@@ -43,6 +43,8 @@
 #ifndef INCLUDED_ASSERT_H
 #define INCLUDED_ASSERT_H
 
+#ifndef PERL_POLLUTE
+
 #ifdef __STDC__
 #define assert(ex)      {if (!(ex))assertionfailed(__FILE__, __LINE__, #ex);}
 void assertionfailed(const char *file, int line, const char *expr);
@@ -50,4 +52,6 @@ void assertionfailed(const char *file, int line, const char *expr);
 #define assert(ex)      {if (!(ex))assertionfailed(__FILE__, __LINE__, (char*)0);}
 #endif
 
+#endif
+
 #endif /* INCLUDED_ASSERT_H */