diff --git a/SConstruct b/SConstruct
index 9df2c5f9f..99577df30 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1879,6 +1879,7 @@ if not preconfigured:
     env.Prepend(CPPPATH = '#deps/mapbox/geometry/include')
     env.Prepend(CPPPATH = '#deps/mapbox/protozero/include')
     env.Prepend(CPPPATH = '#deps/mapbox/polylabel/include')
+    env.Prepend(CPPPATH = '#plugins/input/base/include')
     # prepend deps dir for auxillary headers
     env.Prepend(CPPPATH = '#deps')
 
diff --git a/src/build.py b/src/build.py
index ac35d44f0..b68d33ef1 100644
--- a/src/build.py
+++ b/src/build.py
@@ -87,6 +87,7 @@ if '-DHAVE_TIFF' in env['CPPDEFINES']:
 if '-DHAVE_WEBP' in env['CPPDEFINES']:
    lib_env['LIBS'].append('webp')
    enabled_imaging_libraries.append('webp_reader.cpp')
+   enabled_imaging_libraries.append('webp_io.cpp')
 
 if env['XMLPARSER'] == 'libxml2' and env['HAS_LIBXML2']:
     lib_env['LIBS'].append('xml2')
@@ -152,6 +153,7 @@ else: # unix, non-macos
 
 source = Split(
     """
+    mapnik.cpp
     expression_grammar_x3.cpp
     fs.cpp
     request.cpp