diff --git a/tools/win/msys2-builder b/tools/win/msys2-builder
index f930bed2..a11d20fa 100755
--- a/tools/win/msys2-builder
+++ b/tools/win/msys2-builder
@@ -116,7 +116,7 @@ OPWD="\$PWD"
 export MSYSTEM=MSYS
 . /etc/profile || :
 . ~/.bashrc 2>/dev/null || :
-\$BUILD_ENV
+$BUILD_ENV
 EOF
 
     cd "$OPWD"
@@ -132,7 +132,7 @@ OPWD="\$PWD"
 export MSYSTEM="\$OMSYSTEM"
 . /etc/profile || :
 . ~/.bashrc 2>/dev/null || :
-\$BUILD_ENV
+$BUILD_ENV
 EOF
 
     cd "$OPWD"