diff --git a/ext/rpc/xmlrpc/config.m4 b/ext/rpc/xmlrpc/config.m4
index 774c13b2fb6..2b6b883756e 100644
--- a/ext/rpc/xmlrpc/config.m4
+++ b/ext/rpc/xmlrpc/config.m4
@@ -32,7 +32,9 @@ if test "$PHP_XMLRPC" != "no"; then
     AC_MSG_ERROR(XML-RPC support requires libexpat. Use --with-expat-dir=<DIR>)
   fi
 
-  PHP_ICONV=yes
+  if test "$PHP_ICONV" = "no"; then
+    PHP_ICONV=yes
+  fi
   PHP_SETUP_ICONV(XMLRPC_SHARED_LIBADD, [], [
     AC_MSG_ERROR([iconv not found, in order to build xmlrpc you need the iconv library])
   ])
diff --git a/ext/xmlrpc/config.m4 b/ext/xmlrpc/config.m4
index 774c13b2fb6..2b6b883756e 100644
--- a/ext/xmlrpc/config.m4
+++ b/ext/xmlrpc/config.m4
@@ -32,7 +32,9 @@ if test "$PHP_XMLRPC" != "no"; then
     AC_MSG_ERROR(XML-RPC support requires libexpat. Use --with-expat-dir=<DIR>)
   fi
 
-  PHP_ICONV=yes
+  if test "$PHP_ICONV" = "no"; then
+    PHP_ICONV=yes
+  fi
   PHP_SETUP_ICONV(XMLRPC_SHARED_LIBADD, [], [
     AC_MSG_ERROR([iconv not found, in order to build xmlrpc you need the iconv library])
   ])
diff --git a/ext/xslt/config.m4 b/ext/xslt/config.m4
index 26402760af4..d9a0968a790 100644
--- a/ext/xslt/config.m4
+++ b/ext/xslt/config.m4
@@ -69,7 +69,9 @@ if test "$PHP_XSLT" != "no"; then
       PHP_ADD_LIBRARY(xmltok)
     fi
 
-    PHP_ICONV=yes
+    if test "$PHP_ICONV" = "no"; then
+      PHP_ICONV=yes
+    fi
     PHP_SETUP_ICONV(XSLT_SHARED_LIBADD, [], [
       AC_MSG_ERROR([iconv not found, in order to build sablotron you need the iconv library])
     ])