diff -ru weechat-2.9.orig/configure.ac weechat-2.9/configure.ac
--- weechat-2.9.orig/configure.ac	2020-07-18 13:59:02.000000000 +0200
+++ weechat-2.9/configure.ac	2020-10-06 22:27:28.776471083 +0200
@@ -192,18 +192,6 @@
 fi
 
 # ------------------------------------------------------------------------------
-#                                  pkg-config
-# ------------------------------------------------------------------------------
-
-PKGCONFIG=""
-AC_CHECK_PROGS(PKGCONFIG, pkg-config)
-if test "x$PKGCONFIG" = "x"; then
-    AC_MSG_ERROR([
-*** "pkg-config" couldn't be found on your system.
-*** Try to install it with your software package manager.])
-fi
-
-# ------------------------------------------------------------------------------
 #                                dynamic loader
 # ------------------------------------------------------------------------------
 
@@ -1049,8 +1037,8 @@
 *** or try to install it with your software package manager.])
 else
     AC_MSG_RESULT(yes)
-    GCRYPT_CFLAGS=`libgcrypt-config --cflags`
-    GCRYPT_LFLAGS=`libgcrypt-config --libs`
+    GCRYPT_CFLAGS=`$LIBGCRYPT_CONFIG --cflags`
+    GCRYPT_LFLAGS=`$LIBGCRYPT_CONFIG --libs`
     AC_SUBST(GCRYPT_CFLAGS)
     AC_SUBST(GCRYPT_LFLAGS)
 fi
@@ -1070,8 +1058,8 @@
 *** or try to install it with your software package manager.])
 else
     AC_MSG_RESULT(yes)
-    GNUTLS_CFLAGS=`pkg-config gnutls --cflags`
-    GNUTLS_LFLAGS=`pkg-config gnutls --libs`
+    GNUTLS_CFLAGS=`$PKGCONFIG gnutls --cflags`
+    GNUTLS_LFLAGS=`$PKGCONFIG gnutls --libs`
     AC_SUBST(GNUTLS_CFLAGS)
     AC_SUBST(GNUTLS_LFLAGS)
 fi
@@ -1160,8 +1148,8 @@
 *** or try to install it with your software package manager.])
 else
     AC_MSG_RESULT(yes)
-    ZLIB_CFLAGS=`pkg-config zlib --cflags`
-    ZLIB_LFLAGS=`pkg-config zlib --libs`
+    ZLIB_CFLAGS=`$PKGCONFIG zlib --cflags`
+    ZLIB_LFLAGS=`$PKGCONFIG zlib --libs`
     AC_SUBST(ZLIB_CFLAGS)
     AC_SUBST(ZLIB_LFLAGS)
 fi