diff --git a/cpp/src/flightsql_odbc/flightsql-odbc/build_win32.bat b/cpp/src/flightsql_odbc/flightsql-odbc/build_win32.bat
index c7a476d739a29..bb69711451f3a 100644
--- a/cpp/src/flightsql_odbc/flightsql-odbc/build_win32.bat
+++ b/cpp/src/flightsql_odbc/flightsql-odbc/build_win32.bat
@@ -36,7 +36,9 @@ mkdir build
 
 cd build
 
-if NOT DEFINED ARROW_GIT_REPOSITORY SET ARROW_GIT_REPOSITORY = "https://github.com/apache/arrow"
+if NOT DEFINED ARROW_GIT_REPOSITORY (
+    SET ARROW_GIT_REPOSITORY="https://github.com/apache/arrow"
+    )
 
 cmake ..^
     -DARROW_GIT_REPOSITORY=%ARROW_GIT_REPOSITORY%^