diff --git a/generator/protoc b/generator/protoc
index fe3412b..0fd5506 100755
--- a/generator/protoc
+++ b/generator/protoc
@@ -1,8 +1,17 @@
 #!/usr/bin/env python3
 
 import sys
+import os
+import os.path
 from nanopb_generator import invoke_protoc
 
 if __name__ == '__main__':
+    # Add script directory to path so that protoc-gen-nanopb gets found
+    if getattr(sys, 'frozen', False):
+        mypath = os.path.dirname(sys.executable) # For pyInstaller
+    else:
+        mypath = os.path.dirname(__file__)
+    os.environ["PATH"] = mypath + os.pathsep + os.environ["PATH"]
+
     status = invoke_protoc(['protoc'] + sys.argv[1:])
     sys.exit(status)
diff --git a/generator/protoc.bat b/generator/protoc.bat
index 2538c94..cfd9e43 100644
--- a/generator/protoc.bat
+++ b/generator/protoc.bat
@@ -5,5 +5,5 @@
 
 setLocal enableDelayedExpansion
 set mydir=%~dp0
-python "%mydir%\protoc" %*
+py -3 "%mydir%\protoc" %*
 exit /b %ERRORLEVEL%