diff --git a/NEWS b/NEWS
index 2b21969dffbce..815e975349573 100644
--- a/NEWS
+++ b/NEWS
@@ -27,6 +27,10 @@ PHP                                                                        NEWS
     return value check). (nielsdos, botovq)
   . Fix error return check of EVP_CIPHER_CTX_ctrl(). (nielsdos)
 
+- Readline:
+  . Fixed bug GH-19250 and bug #51360 (Invalid conftest for rl_pending_input).
+    (petk, nielsdos)
+
 - SOAP:
   . Fixed bug GH-18640 (heap-use-after-free ext/soap/php_encoding.c:299:32
     in soap_check_zval_ref). (nielsdos)
diff --git a/ext/readline/config.m4 b/ext/readline/config.m4
index 209f92b6e0a76..873b116fcffb6 100644
--- a/ext/readline/config.m4
+++ b/ext/readline/config.m4
@@ -47,13 +47,6 @@ if test "$PHP_READLINE" && test "$PHP_READLINE" != "no"; then
     -L$READLINE_DIR/$PHP_LIBDIR $PHP_READLINE_LIBS
   ])
 
-  PHP_CHECK_LIBRARY(readline, rl_pending_input,
-  [], [
-    AC_MSG_ERROR([invalid readline installation detected. Try --with-libedit instead.])
-  ], [
-    -L$READLINE_DIR/$PHP_LIBDIR $PHP_READLINE_LIBS
-  ])
-
   PHP_CHECK_LIBRARY(readline, rl_callback_read_char,
   [
     AC_DEFINE(HAVE_RL_CALLBACK_READ_CHAR, 1, [ ])
@@ -75,6 +68,26 @@ if test "$PHP_READLINE" && test "$PHP_READLINE" != "no"; then
     -L$READLINE_DIR/$PHP_LIBDIR $PHP_READLINE_LIBS
   ])
 
+  CFLAGS_SAVE=$CFLAGS
+  LDFLAGS_SAVE=$LDFLAGS
+  LIBS_SAVE=$LIBS
+  CFLAGS="$CFLAGS $INCLUDES"
+  LDFLAGS="$LDFLAGS -L$READLINE_DIR/$PHP_LIBDIR"
+  LIBS="$LIBS -lreadline"
+
+  dnl Sanity and minimum version check if readline library has variable
+  dnl rl_pending_input.
+  AC_CHECK_DECL([rl_pending_input],, [AC_MSG_FAILURE([
+      Invalid readline installation detected. Try --with-libedit instead.
+    ])], [
+      #include <stdio.h>
+      #include <readline/readline.h>
+    ])
+
+  CFLAGS=$CFLAGS_SAVE
+  LDFLAGS=$LDFLAGS_SAVE
+  LIBS=$LIBS_SAVE
+
   AC_DEFINE(HAVE_HISTORY_LIST, 1, [ ])
   AC_DEFINE(HAVE_LIBREADLINE, 1, [ ])