diff --git a/tests/preproc/src/main.c b/tests/preproc/src/main.c
index e07e1761..9ee24a54 100644
--- a/tests/preproc/src/main.c
+++ b/tests/preproc/src/main.c
@@ -1,7 +1,11 @@
 
 #if A
+const char* c = "foo /*";
   #if B
+const char* d = " bar */";
+// /*
     #if C
+// */
       #include "a.h"
     #else
       #include "b.h"
diff --git a/waflib/Tools/c_preproc.py b/waflib/Tools/c_preproc.py
index ececfc50..b0a60952 100644
--- a/waflib/Tools/c_preproc.py
+++ b/waflib/Tools/c_preproc.py
@@ -138,7 +138,7 @@ skipped   = 's'
 def repl(m):
 	"""Replace function used with :py:attr:`waflib.Tools.c_preproc.re_cpp`"""
 	s = m.group(0)
-	if s.startswith('/'):
+	if s[0] == '/':
 		return ' '
 	return s