diff --git a/pkgs/development/pharo/vm/build-vm.nix b/pkgs/development/pharo/vm/build-vm.nix
index e2ed4dcb2392..2f2db1293c72 100644
--- a/pkgs/development/pharo/vm/build-vm.nix
+++ b/pkgs/development/pharo/vm/build-vm.nix
@@ -59,7 +59,7 @@ stdenv.mkDerivation rec {
   # Note: --with-vmcfg configure option is broken so copy plugin specs to ./
   preConfigure = ''
     cd opensmalltalk-vm
-    cp build.${flavor}/pharo.cog.spur/plugins.{ext,int} .
+    cp build."${flavor}"/pharo.cog.spur/plugins.{ext,int} .
   '';
 
   # (No special build phase.)
diff --git a/pkgs/development/pharo/wrapper/pharo-vm.sh b/pkgs/development/pharo/wrapper/pharo-vm.sh
index 7ccab99cd763..d5bd1a2d8018 100644
--- a/pkgs/development/pharo/wrapper/pharo-vm.sh
+++ b/pkgs/development/pharo/wrapper/pharo-vm.sh
@@ -53,5 +53,5 @@ fi
 
 # Run the VM
 set -f
-exec -- ${vm} $@
+exec -- "${vm}" "$@"