5 files changed, 15 insertions, 0 deletions
diff --git a/ext/digest/md5/extconf.rb b/ext/digest/md5/extconf.rb
index ddfdb707f2..803741a6d9 100644
--- a/ext/digest/md5/extconf.rb
+++ b/ext/digest/md5/extconf.rb
@@ -22,4 +22,7 @@ have_header("sys/cdefs.h")
 
 $preload = %w[digest]
 
+if try_compile("", flag = " -Wno-deprecated-declarations")
+  $warnflags << flag
+end
 create_makefile("digest/md5")
diff --git a/ext/digest/rmd160/extconf.rb b/ext/digest/rmd160/extconf.rb
index cc361e3d2b..8d8cdee6ba 100644
--- a/ext/digest/rmd160/extconf.rb
+++ b/ext/digest/rmd160/extconf.rb
@@ -21,4 +21,7 @@ have_header("sys/cdefs.h")
 
 $preload = %w[digest]
 
+if try_compile("", flag = " -Wno-deprecated-declarations")
+  $warnflags << flag
+end
 create_makefile("digest/rmd160")
diff --git a/ext/digest/sha1/extconf.rb b/ext/digest/sha1/extconf.rb
index fa9945cd43..77a4b2b847 100644
--- a/ext/digest/sha1/extconf.rb
+++ b/ext/digest/sha1/extconf.rb
@@ -21,4 +21,7 @@ have_header("sys/cdefs.h")
 
 $preload = %w[digest]
 
+if try_compile("", flag = " -Wno-deprecated-declarations")
+  $warnflags << flag
+end
 create_makefile("digest/sha1")
diff --git a/ext/digest/sha2/extconf.rb b/ext/digest/sha2/extconf.rb
index a8f0198cf0..e0634245a9 100644
--- a/ext/digest/sha2/extconf.rb
+++ b/ext/digest/sha2/extconf.rb
@@ -26,5 +26,8 @@ have_header("sys/cdefs.h")
 $preload = %w[digest]
 
 if have_type("uint64_t", "defs.h", $defs.join(' '))
+  if try_compile("", flag = " -Wno-deprecated-declarations")
+    $warnflags << flag
+  end
   create_makefile("digest/sha2")
 end
diff --git a/ext/openssl/extconf.rb b/ext/openssl/extconf.rb
index 3cea2ded7b..44ea3e5d0e 100644
--- a/ext/openssl/extconf.rb
+++ b/ext/openssl/extconf.rb
@@ -146,6 +146,9 @@ have_struct_member("X509_ATTRIBUTE", "single", "openssl/x509.h")
 
 message "=== Checking done. ===\n"
 
+if try_compile("", flag = " -Wno-deprecated-declarations")
+  $warnflags << flag
+end
 create_header
 create_makefile("openssl")
 message "Done.\n"