diff --git a/Makefile.am b/Makefile.am
index 16a7da40..c5b8a1fa 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -34,6 +34,8 @@ libuv_la_SOURCES = src/fs-poll.c \
                    src/version.c
 
 if SUNOS
+# Can't be turned into a CC_CHECK_CFLAGS in configure.ac, it makes compilers
+# on other platforms complain that the argument is unused during compilation.
 libuv_la_CFLAGS += -pthread
 endif
 
@@ -81,7 +83,6 @@ else  # WINNT
 
 include_HEADERS += include/uv-unix.h
 AM_CPPFLAGS += -I$(top_srcdir)/src/unix
-libuv_la_CFLAGS += -g --std=gnu89 -pedantic -Wall -Wextra -Wno-unused-parameter
 libuv_la_SOURCES += src/unix/async.c \
                    src/unix/atomic-ops.h \
                    src/unix/core.c \
diff --git a/configure.ac b/configure.ac
index fe2d6327..c9b2c41c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -24,6 +24,9 @@ AC_ENABLE_SHARED
 AC_ENABLE_STATIC
 AC_PROG_CC
 AM_PROG_CC_C_O
+CC_CHECK_CFLAGS_APPEND([-g])
+CC_CHECK_CFLAGS_APPEND([-std=gnu89])
+CC_CHECK_CFLAGS_APPEND([-pedantic])
 CC_CHECK_CFLAGS_APPEND([-Wall])
 CC_CHECK_CFLAGS_APPEND([-Wextra])
 CC_CHECK_CFLAGS_APPEND([-Wno-unused-parameter])