diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 9e76c5b11..5606c4139 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -877,6 +877,10 @@ int dummy;
 
     def generate_single_java_compile(self, src, target, compiler, outfile):
         deps = [os.path.join(self.get_target_dir(l), l.get_filename()) for l in target.link_targets]
+        generated_sources = self.get_target_generated_sources(target)
+        for rel_src, gensrc in generated_sources.items():
+            if rel_src.endswith('.java'):
+                deps.append(rel_src)
         args = []
         args += compiler.get_buildtype_args(self.get_option_for_target('buildtype', target))
         args += self.build.get_global_args(compiler, target.is_cross)
diff --git a/mesonbuild/environment.py b/mesonbuild/environment.py
index f45f91bf1..2a6f750b4 100644
--- a/mesonbuild/environment.py
+++ b/mesonbuild/environment.py
@@ -803,8 +803,8 @@ class Environment:
             p, out, err = Popen_safe(exelist + ['-version'])
         except OSError:
             raise EnvironmentException('Could not execute Java compiler "%s"' % ' '.join(exelist))
-        version = search_version(err)
         if 'javac' in out or 'javac' in err:
+            version = search_version(err if 'javac' in err else out)
             return JavaCompiler(exelist, version)
         raise EnvironmentException('Unknown compiler "' + ' '.join(exelist) + '"')
 
diff --git a/test cases/java/8 codegen custom target/com/mesonbuild/meson.build b/test cases/java/8 codegen custom target/com/mesonbuild/meson.build
index 67b98a4cd..030994154 100644
--- a/test cases/java/8 codegen custom target/com/mesonbuild/meson.build	
+++ b/test cases/java/8 codegen custom target/com/mesonbuild/meson.build	
@@ -4,5 +4,5 @@ config_file = custom_target('confgen',
                             input : 'Config.java.in',
                             output : 'Config.java',
                             command : [python, '-c',
-                              'import shutil; import sys; shutil.copy(sys.argv[1], sys.argv[2])',
+                              'import shutil, sys, time; time.sleep(1); shutil.copy(sys.argv[1], sys.argv[2])',
                               '@INPUT@', '@OUTPUT@'])