diff --git a/configure.ac b/configure.ac
index 80f9774..48a8918 100644
--- a/configure.ac
+++ b/configure.ac
@@ -109,13 +109,6 @@ cc_TRY_CFLAGS([-Wshadow])
 
 AC_SUBST([CFLAGS], ["$CFLAGS $SUPPORTED_CFLAGS"])
 
-dnl Check to see if function prototypes are understood by the compiler.
-dnl This test must precede tests of compiler characteristics like that
-dnl for the inline keyword, since it may change the degree to which the
-dnl compiler supports such features.
-dnl ------------------------------------------------------------
-AM_C_PROTOTYPES
-
 dnl Check if C the compiler does not fully support the ANSI C qualifier
 dnl `const'.
 dnl ------------------------------------------------------------