diff --git a/configure.ac b/configure.ac
index 707f9216..ea08dee6 100644
--- a/configure.ac
+++ b/configure.ac
@@ -76,9 +76,7 @@ AX_GCC_BUILTIN([__builtin_clzll])
 AX_GCC_BUILTIN([__builtin_clzl])
 
 # Checks for library functions.
-AC_FUNC_MALLOC
-AC_FUNC_REALLOC
-AC_CHECK_FUNCS([floor getdelim gettimeofday memmove memset pow sqrt strchr strstr strtol])
+AC_CHECK_FUNCS([floor getdelim gettimeofday memmove memset malloc realloc pow sqrt strchr strstr strtol])
 
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([